In the UK and Commonwealth, an oath of allegiance is a promise to be loyal to the monarch, their heirs and successors. Also known as ‘swearing in’, it is pledged in various contexts, including at the beginning of a Parliament and when government ministers assume office. The allegiance is pledged to the monarch as the personification of the Crown – the symbol of British state authority.

But oaths of allegiance can be deeply problematic. What happens when an individual, a political party, or, indeed, an entire nation, does not recognise the monarch as head of state and wants to cut ties with the British Crown? While this is not the only constitutional challenge presented in such circumstances, it is one which is increasingly being encountered as republican sentiment sweeps throughout the King’s realms.

Last month, Grenada announced that both its government and opposition parties would be dropping the oath of allegiance to the British Crown, amid a wider movement on the Caribbean island to remove King Charles as head of state. In what it described as ‘constitutional progress’,  the Government announced that Parliament had agreed bills to amend the country’s constitution so as to remove the words ‘His Majesty King Charles the Third, His Heirs and Successors’ from the oath of allegiance and replace them simply with ‘Grenada’. Prime Minister Dickon Mitchell said that the amendment ‘demonstrates our shared commitment to national identity and (that)… our allegiance belongs to Grenada and its people.’ Tourism and Culture Minister Adrian Thomas added that the move formed part of a broader trend to decolonise society, assert the country’s independence, and reform the constitution.

The oath of allegiance is seen as a mark of sovereignty, so for nations seeking (further) independence from the British Crown it is a hugely important symbol. Indeed, in a further symbolic act of liberation, Grenada’s Constitution (Oath of Allegiance) (Amendment) (NO. 1) Bill 2025  was enacted on 1 August 2025, known as Emancipation Day – the day that slavery was abolished in the British Empire. There has been no official reaction from the monarchy to the amendment. However, King Charles has previously said that, for example, it would be ‘a matter for the Australian public to decide‘ whether the country becomes a republic. Similarly, following his 2022 tour of the Caribbean, Prince William stated that ‘it is up to the people to decide‘ on their future. The royal silence perhaps speaks volumes, however, as removing the oath of allegiance to the monarch is indeed often the first step on the path to becoming a republic. For example, two months prior to becoming a republic in November 2021, the Barbados Parliament had to amend the constitution via the Constitution (Amendment) (No. 2) Bill 2021 so as to declare that the oath of allegiance would be to the state of Barbados rather than to the then-Queen.

It is not just in Grenada that the oath of allegiance to King Charles is being tested. Since Canada’s founding, legislators have been required under s.128 Constitution Act 1867 to swear an oath of allegiance to the British monarch before they can take their seat in the legislative assembly. But in 2022, the province of Québec – where the monarch is viewed more negatively than in other regions due its unique history as a French-speaking region – passed a law making the oath of allegiance to the monarch optional for Québécois members of the legislature. Known as Bill 4, the law was introduced after the ascension of King Charles III, when three Parti Québécois and 11 Québec Solidaire politicians refused to swear the oath to ‘be faithful and bear true allegiance to His Majesty King Charles III and his heirs and successors according to law’. Bill 4 amends the 1867 Act by adding a simple section declaring that s.128 ‘does not apply to Québec’. The following year, a Liberal Party MP introduced a Private Member’s Bill seeking to remove the 156-year-old oath requirement for all Canadian legislators. Bill C-347 would have meant that lawmakers needed only swear to ‘carry out duties in the best interest of Canada while upholding its Constitution’, although it was ultimately defeated. And in December 2024, newly-elected members of Dawson City Council in the Yukon Territory refused to pledge allegiance to King Charles during their swearing-in ceremony in a show of solidarity with an indigenous council member who raised concerns about the British Crown’s colonial history. Meanwhile, at the official opening of the 48th Australian Parliament last month, Federal MP Bob Katter also refused to swear allegiance to King Charles III, instead replying that he ‘swears allegiance to the Australian people.’

Similar moves can be seen closer to home. Just last month, the SNP MSP and former minister, Kevin Stewart, followed in Grenada’s footsteps by submitting a motion stating that MSPs should ‘pledge allegiance to the people of Scotland and not an unelected monarch’. The motion’s full text reads:

that the Parliament commends Grenada’s reported decision to drop the oath of allegiance to the British crown and replace it with a pledge of allegiance to Grenada; recognises that the people of Scotland are sovereign, and believes that Scotland’s Parliament should have the power to follow Grenada’s lead and have its members pledge allegiance to the people of Scotland and not an unelected monarch.

The motion has been supported by more than a dozen SNP MSPs, as well as MPs from Scottish Labour, Scottish Greens, and Independents. In Holyrood, s.84 Scotland Act 1998 requires MSPs to swear to be ‘faithful and bear true allegiance’ to the monarch in order to take part in parliamentary business. The swearing-in ceremony last happened following the 2021 election, when then-First Minister Nicola Sturgeon prefaced taking the oath by stating that ‘the Scottish National Party pledges loyalty to the people of Scotland, in line with the Scottish constitutional tradition of the sovereignty of the people.’ Her comments were echoed by Scottish Greens co-leader Patrick Harvie, who similarly prefaced that:

on behalf of the Scottish Green Party, I would like to reassert that our allegiance lies with the people of Scotland, who elected this parliament and who are sovereign, and that we look forward to the day when they can choose their own elected head of state.

The motion from Kevin Stewart has since sparked broader calls in Scotland for a referendum on the oath of allegiance sworn by MSPs. Plaid Cymru has made similar calls in Wales, where a petition was launched to make the oath of allegiance to the monarch, currently required under s. 23 Government of Wales Act 2006, optional for members of the Senedd. Swearing the oath is certainly not merely a piece of ‘constitutional theatre’: in both nations a failure to take the oath within two months will see MSPs and MSs lose their seats in their respective Parliaments. This can be contrasted with Northern Ireland, where there is no oath of allegiance required for MLAs in Stormont.

The controversy over oaths of allegiance is nothing new. For example, in the Westminster Parliament MPs representing Sinn Féin have long refused to swear the Parliamentary Oath since, as supporters of a united Ireland, they do not recognise the British monarch as head of state. S.1 Parliamentary Oaths Act 1866 provides that the Parliamentary Oath must be ‘made and subscribed by members of both Houses of Parliament on taking their seats in every Parliament’. The Oath, found in s.2 Promissory Oaths Act 1868, is ‘to be faithful and bear true allegiance to His Majesty King Charles the Third, his heirs and successors’. Under s. 5 Parliamentary Oaths Act 1866, an MP who has not taken the oath cannot participate in formal proceedings of the House of Commons, sit in the chamber, or vote in divisions. This is why Sinn Féin MPs do not take their seats in the House of Commons. And under a 1924 ruling by the Speaker of the House of Commons, MPs who refuse to take the Oath are also not paid a salary.

In 1999, then-Sinn Féin MP and future deputy First Minister of Northern Ireland, Martin McGuinness, challenged the requirement to take the Parliamentary Oath to the British monarch in the European Court of Human Rights (ECtHR), arguing that it breached his right to freedom of expression under Article 10 of the Convention. However, the Court unanimously held that the requirement did not contravene Article 10, which may be restricted ‘for the protection of the rights of others’ under Article 10 (2) (Martin McGuinness v United Kingdom, 35911/98). The ECtHR found that this phrase could extend to the protection of constitutional principles which underpin the rights of others in a democratic society. The requirement to take the Parliamentary Oath was considered such a constitutional principle as, in the Court’s view, it affirmed loyalty to the democratic workings of the State.

But three decades on, the oath of allegiance remains just as controversial as ever, if not more so. And it is not hard to see why. The very word ‘allegiance’ derives from the Anglo-Norman French alleggeance, referring to the loyalty of a liegeman to his feudal King (see Lewis Kennedy, ‘How to modernise the law of treason around a new version of allegiance’ (2021) Judicial Review 117, 119). It quite literally ‘evokes a sense of deference, subservience even, to the monarchy’ in a way which has been described – contrary to the ECtHR’s ruling – as ‘hopelessly undemocratic’ (Ibid). For reluctant subjects who hold different ideas about what their relationship with the monarch should be, the oath of allegiance is fundamentally problematic – as we are increasingly seeing in the current social context. For example, Malik, writing earlier this year, observes that as more research uncovers its historic links to slavery, more Caribbean countries are looking for ways to ‘ditch the British monarchy’ and ‘push for colonial freedom’. We have already seen Barbados become a republic in 2022, and in 2024 Jamaica tabled a bill to follow suit, with several others signalling similar intentions. But some countries are taking a more subtle approach. For example, earlier this year Belize removed Queen Elizabeth II’s image from its banknotes. Oaths of allegiance, like banknotes, can be seen as ‘vestiges of colonialism‘. For nations that want to be seen as equals, not ex-colonies, swearing a ‘subservient’ oath of allegiance to a British monarch who ‘embodies imperial legacies’ is ‘insulting’. Elsewhere, in the home nations – where ‘nationalism is rising‘ and, in the case of Scotland and Northern Ireland, the two largest political parties want to leave the UK – the oath of allegiance is a deeply symbolic tie to the Crown which they are eager to sever.

But current legal and constitutional frameworks simply do not allow for such severance in practice. For example, the Scottish Parliament does not presently have the competence to modify s.84 of the 1998 Act requiring the Oath, as under Schedule 4(d) it is a protected enactment. Modifications are not, however, theoretically impossible. Over the years, changes have been made to other aspects of the oath of allegiance to recognise evolving social attitudes. For example, s.5 Oaths Act 1978 allows MPs to take a non-religious ‘solemn affirmation’ in place of swearing the religious oath. It shows that the oath can evolve, but interestingly there apparently seems to be more flexibility regarding religious beliefs than political/republican beliefs.

The oath of allegiance has been described as ‘one of the creaky old traditions of Britain’s creaky old constitutional monarchy.’ Under the weight of mounting calls for greater sovereignty, both around the Commonwealth and in the UK, it is arguably creaking like never before. When, in 2008, a group of 22 parliamentarians called for the oath to be made voluntary, the idea was dismissed as ‘constitutional vandalism’. But arguably the social context in which oaths are made has now changed, and whether a pledge that was once considered a fundamental constitutional requirement will continue to be sworn to the King, his heirs, and successors is much more debatable.

I am grateful to the editors for their helpful comments on earlier drafts of this post.

Francesca Jackson is a PhD student at Lancaster University.

(Suggested citation: F. Jackson, ‘The Oath of Allegiance, and the Battle for Independence’, U.K. Const. L. Blog (17th October 2025) (available at https://ukconstitutionallaw.org/))