There’s no proper place for referenda in the British political system, other than – perhaps – as a people’s veto. A national poll in lieu of royal assent could work, but electors should not be able to give orders to Parliament other than through their MPs.
Much of this was discussed before the 1975 referendum. The UK had joined the EEC under Heath’s conservative government in 1972. Labor promised to renegotiate the EEC treaty and put it up for a referendum, and did both on returning to government in 1974. The Labor cabinet was split on the renegotiated treaty but thanks to Conservative support the Commons ratified it by a significant majority (396-170). After this, the referendum was essentially a confirmatory vote.
It went down well but, in some politicians’ view, it was held for the wrong reasons and set a dubious precedent. As Robert Lindsay, Lord Balniel (a Tory), announced in his maiden speech:
But every person in this House knows – indeed, virtually every person in the country is well aware of the fact – that the holding of the Referendum was to try to quieten difficulties which had arisen some years ago in the Labour Party when they were in Opposition.
…it is frankly difficult to deny that this does not touch upon the sovereignty of Parliament… If I may paraphrase his [Cabinet minister Harold Lever’s] words of not so long ago, he said that a Referendum is alien to our Parliamentary system; incidentally, exactly the words which were used by Lord Attlee [in 1945]. He went on to say that this is a diminution of Parliamentary sovereignty, and he used phrases about the derogation of the power of Parliament. Those are not my words; they are the words of a Minister in the present Cabinet…
If we embark on this course we must not delude ourselves as to what the consequences will be. The demand for a repeat performance will come very quickly. “Give us a Referendum” will be the battle cry of every campaigner.
Lord Byers, a Liberal life peer, agreed:
I have great fears… of the damage which this introduction into our Parliamentary procedure will wreak on our whole system of representative Government. I do not believe it will be possible to limit the case of the referendum to the one issue of the EEC or to constitutional issues alone… It will spread and every time it is used it will weaken the authority of the elected Member of Parliament and will further undermine Parliamentary democracy.
I resent the fact that this device has been proposed for no better reason than to try to hold together the Labour Party in a state of sham unity, in which collective Cabinet responsibility has been shelved in favour of that ghastly business of an agreement to differ.
All of this could be justly repeated in 2016, only the party in the “state of sham unity” would be the Conservatives.
On the other hand, A. V. Dicey, the great scholar of the British constitution, might have approved a plebiscite – but not the Brexit one. Dicey argued that referenda would enable the nation to veto parliamentary acts of constitutional importance. The people, in his view, should be able to block changes to the country’s constitution even if voted in by Parliament. (In particular, Irish Home Rule was Dicey’s nightmare.) It wasn’t obvious in 1975 that the EEC treaty was much more than a trade deal and would ever transform the UK’s own political institutions, so it isn’t obvious that Dicey would have supported the 1975 referendum. His logic, however, could have justified calling a referendum on the judicial reforms of the 2000s (above all the abolition of the double jeopardy principle). The Maastricht and Lisbon treaties would have presumably qualified, too. Now, if Parliament had passed an EU dissociation act in 2016, Diceyan reasoning would have likewise suggested that it be submitted to popular vote.
It wasn’t the case, obviously – it was a case of “the people” giving a concise but imprecise order to Parliament bypassing the legitimate, electoral route. Dicey never envisaged referenda as citizens’ initiatives – he only accepted the “negative” sort, held to affirm or reject laws already passed by Parliament.
Finally, if Parliament manages to pass an EU withdrawal bill, putting it up for a popular vote would be in Dicey’s spirit. That’s Labor’s public vote proposal – “a confirmatory vote” as deputy leader Tom Watson called it.