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