Neal Ascherson wrote in the New York Review of Books in 2017:
The parliamentary sovereignty dogma was enshrined by the great Victorian jurist A.V. Dicey. But, funnily enough, Dicey changed his mind about referendums at the end of his life. He feared that his teaching had created a Leviathan: a cabinet entrenched by parliamentary majority that could act without any control at all. So he proposed “negative” referendums. The voters wouldn’t propose anything, but they could veto a government measure that citizens disliked. But nobody took the old man seriously. They suggested that he merely wanted public opinion to block two reforms he dreaded: Home Rule for Ireland and votes for women.
Dicey published Ought the Referendum to be Introduced into England? in 1890, when he was 55 – only five years after the first edition of his Introduction to the Study of the Law of the Constitution appeared. He would only retire from teaching at Oxford nineteen years later. In 1896, he would become the first professor of law at the newly established London School of Economics. Even if he had passed his intellectual peak by 1890, he couldn’t have gone very far downhill by then, and he definitely wasn’t (yet) a senile superannuated Victorian.
In other words, Dicey went public with his advocacy for the people’s veto long before his faculties and reputation went into decline. In fact, he did so between the failure of the first Home Rule Act in the Commons (1886) and the death of the second one in the Lords (1893). It was in 1886, over Irish Home Rule, that Dicey broke with Gladstone’s Liberals and joined the Liberal Unionists. He remained the brightest of Unionist minds until his death, which more or less coincided with the death of Unionism outside of the six Ulster counties.
What Ascherson calls the “parliamentary sovereignty dogma” refers to legal sovereignty: the notion that parliament, and parliament alone, can make and unmake any law, and courts may not void such laws. Political sovereignty, according to Dicey, was something different: in this sense, Parliament was still constrained by popular opinion (certain unpopular laws would be impossible to enforce) and by its own conscience. In 1890, Dicey merely suggested that certain types of laws be submitted to referenda for final approval, in line with his distinction between Parliament’s legal and political supremacy.
In 1914, however, Dicey claimed in a private letter that the King had retained the power to veto a bill (last done in 1708), even though the old man advised strongly against it. Rather, Dicey suggested to George V that he, the King, force a new election by firing the PM and appointing an opposition politician instead. The theorist and the monarch were both known to oppose Home Rule.
Hugh Tulloch wrote in A. V. Dicey and the Irish Question by (1980):
The advocate of the rule of law came to support the right of rebellion in Ulster; the upholder of parliamentary sovereignty became the leading publicist for the referendum…
“The institutions of an ancient realm are not exactly the corpus vile on which theorists hard pressed by the practical difficulties of the political situation can be allowed to try unlimited experiments,” he wrote in 1893. Perhaps Dicey ended up doing precisely this.
Tulloch, who lectured at the University of Bristol in 1971-2003, produced among other works a biography of Lord Acton (the historian) and an analysis of John Bryce’s American Commonwealth (Bryce was Dicey’s friend and opponent; together, they traveled to the US in 1870).