100 years of the Government of Ireland Act: how it provided a model for Westminster-Edinburgh relations

The Government of Ireland Act 1920 is 100 years old tomorrow. David Torrance examines the legislation and its impact, arguing that a number of the constitutional conventions that regulate relations between Westminster and Holyrood have roots in those that applied to Stormont between 1920 and 1972.

Wednesday 23 December marks the centenary of royal assent for the Government of Ireland Act 1920 (the ‘1920 Act’). That this created the part of the UK known as ‘Northern Ireland’ and its border is well known, but its devolution settlement – a parliament, government, governor and prime minister – has largely faded from public consciousness.

As the historian Graham Walker has observed, Northern Ireland ‘serves as a reminder that devolution and constitutional change has a long, complex, and fascinating history, and did not just appear magically at the end of the twentieth century’ [1]. Indeed, this blog will argue that many of the constitutional conventions now associated with Holyrood-Westminster relations have antecedents in those which developed between Stormont and the UK parliament between 1921 and 1972. There was also one major difference, self-determination, analysis of which concludes this piece.

A ‘sound custom’ of non-interference

Speaking during Lords consideration of the Scotland Bill in 1998, Lord Sewel observed that ‘as happened in Northern Ireland earlier in the century’ the government would expect ‘a convention to be established that Westminster would not normally legislate with regard to devolved matters in Scotland without the consent of the Scottish parliament’. This would later come to be known as the Sewel convention.

The Northern Ireland precedent acknowledged by Lord Sewel was established in 1922 when Home Secretary Edward Shortt (who had responsibility for GB-NI relations at the time, as there was no Northern Ireland Office) advised withholding royal assent for a bill abolishing the Single Transferable Vote method for local government elections (a matter ‘transferred’ to Belfast). When Northern Ireland’s Prime Minister Sir James Craig and his Cabinet threatened to resign, assent was granted.

By 1953, a Treasury document could state that:

In practice the United Kingdom Parliament refrains from legislating on matters with which the Northern Ireland Parliament can deal, except at the request and with the consent of Northern Ireland. It is recognised that any departure from this practice would be open to objection as impairing the responsibility which has been placed on the Northern Ireland Parliament and Government.

HM Treasury, Northern Ireland, the Channel Islands and the Isle of Man: A Treasury Paper, December 1953, page 9

At the same time, the UK parliament and government could and did apply pressure. In 1932 the Government of Northern Ireland reluctantly passed legislation authorising a general revaluation of rateable properties when Westminster threatened to legislate directly.

By the late 1960s, what Northern Ireland Prime Minister Terence O’Neill called the ‘sound custom’ of non-interference by the UK Parliament in transferred matters was breaking down. The UK Prime Minister Harold Wilson had made it clear, O’Neill said in a broadcast, ‘that if we did not face up to our problems the Westminster Parliament might well decide to act over our heads’. Although Westminster refrained from legislating in devolved areas, between 1969 and Direct Rule in 1972 it was much more interventionist.

The Special Formula

As well as a proto-Sewel Convention, Northern Ireland also had a precursor to the Barnett formula. Financial relations between Great Britain and Northern Ireland were incredibly complex. There was no ‘block grant’ but instead a series of bilateral negotiations covering matters like social security, agricultural subsidies and ad hoc grant-in-aid (the last of which continues to this day).

The financial provisions of the 1920 Act – self-sufficiency and an Imperial Contribution to the UK Exchequer – broke down almost immediately. A special arbitration committee recommended in 1925 that the Contribution become a final rather than initial ‘charge’ to the Northern Ireland Exchequer. It was also decided that Northern Ireland’s total expenditure on local services was to ‘keep pace’ with total expenditure in Great Britain ‘on an equivalent basis per head of population’.

Under this ‘Special Formula’, expenditure per head of population was fixed at £5 in Northern Ireland and £3.90 in Great Britain, with variations from these standards in GB ‘annually translated into equivalent figures for Northern Ireland’.

Although the Special Formula came under strain in the 1930s, the principle held. In 1966-67 there was an annual ‘subvention’ of £52 million from Great Britain to Northern Ireland, rising to £313 million in 1973-74. In 1968, the Labour minister and diarist Richard Crossman noted that neither the Chancellor nor the Chief Secretary understood the formula under which this subvention was calculated. Direct Rule in 1972 replaced this system with a much simpler ‘block grant’, as in Scotland and Wales.

Further powers and ‘Dominion status’

As an autonomous legislature within the United Kingdom, the Parliament of Northern Ireland often considered the extent of its powers. Strikingly, many of the resulting debates look familiar from the viewpoint of post-1999 Scotland. Just as the Scotland Acts of 2012 and 2016 extended the legislative competence of the Scottish Parliament, the Parliament of Northern Ireland’s powers were broadened or clarified by six UK Acts between 1928 and 1962.

Some Ulster Unionists (who dominated Stormont throughout its existence between 1921 and 1972) felt constrained by Section 75 of the 1920 Act, which declared Westminster’s legislative supremacy. They proposed seeking Dominion status, often in response to perceived threats to Northern Ireland’s constitutional status from Westminster governments. The prospect of what would later be called ‘fiscal autonomy’ was much explored by academics and economists.

They generally concluded it would be costly, largely on account of the balance of financial relations between the two parts of the United Kingdom. In a comprehensive 1965 study, the political scientist R. J. Lawrence concluded that if Northern Ireland was required to fund its own ‘Imperial’ services, then ‘she would either have to cut domestic spending by some £50m a year or raise that sum by taxation’.


The 1920 Act did not explicitly reserve the constitution or the Union of Great Britain and Northern Ireland in the manner of the Scotland Act 1998. And here we conclude with the main point of difference between the two devolved administrations: the Government of Northern Ireland possessed the de facto power of self-determination during its half century of existence, although this was often more theoretical than real.

‘Self-determination’ had been a fixture of Ulster Unionist discourse since the Home Rule debates of the 1880s, but it was acknowledged for the first time by the Anglo-Irish Treaty of 1921. Article 12 stated that the Parliament of Northern Ireland had a month (inevitably dubbed the ‘Ulster Month’) in which to decide whether the territory of Northern Ireland (‘as determined in accordance with the wishes of the inhabitants’) should remain in, or opt out of, the Irish Free State.

It wasted no time in doing so following the birth of the Free State on 6 December 1922. Both Houses resolved to make an address to King George V on 7 December, which was received at Sandringham the following day. The monarch responded in the language required by statute, concluding that he had caused his ‘Ministers and the Irish Free State Government to be so informed’.

This self-determination was restated in the Ireland Act 1949, Section 1 of which affirmed that ‘in no event’ would Northern Ireland ‘cease to be part of His Majesty’s dominions and of the United Kingdom without the consent of the Parliament of Northern Ireland’. Sir Basil Brooke, the then Prime Minister of Northern Ireland, believed the 1949 Act ‘placed the fate of Ulster in our own hands’ in that Stormont could veto any London-instigated moves to reunify the island of Ireland.

For this reason, the constitutionalist Harry Calvert believed a ‘fourth estate’ had been added to that of the UK Commons, Lords and the sovereign, in that the Parliament of Northern Ireland was recognised as ‘the voice of Northern Ireland for the purpose of negotiations or agreements amending the treaty of 1800’.

This ‘principle of consent’ was transferred from the prorogued Parliament of Northern Ireland to the ‘people of Northern Ireland’ by the Northern Ireland Constitution Act 1973, as subsequently confirmed by the Belfast/Good Friday Agreement and Northern Ireland Act 1998. Both made provision for periodic referendums on Northern Ireland’s constitutional status, something that does not form an unequivocal part of Scotland’s contested devolution settlement. 

This post summarises some of the research discussed in David’s paper, Parliament and Northern Ireland, 1921-2021, published by the House of Commons Library. That paper is summarised by a short blog on the subject, 100 years since the Government of Ireland Act 1920.


[1] Graham Walker, ‘Northern Ireland: devolution pioneers’, in P J Roche & B Barton (editors), The Northern Ireland Question: Perspectives on Nationalism and Unionism, (Wordzworth) 2020, page 81.

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About the author

David Torrance is a Senior Library Clerk at the House of Commons Library, specialising in devolution, monarchy and the constitution.