Back in 1975, the last time we had a referendum on whether we should continue to be a member of the European Union, the Government spelled out in advance that it would not necessarily do what the people decided.

The Labour government of Harold Wilson made it clear the referendum was advisory — the ultimate opinion poll if you like — but that “the British parliament in Westminster retains the final right to repeal the Act which took us into the Market on January 1, 1973”.

People seem not to understand that this is still the case. The referendum next week is not binding and the result does not constitute a final irrevocable decision either way.

People talk about notifying the EU of our intention to leave and then having two years to organise it, but that is not the core issue either.

If we are to leave the EU, it will take a fully fledged Act of Parliament to do so. It is hard to see how a notice to quit under Article 50 could be served, given it sets that process in train without the agreement of Parliament.

But that should have to go through the Commons and the Lords, plus all the committee stages, just like any other Act of Parliament. That is a big ask for a Tory Government with a majority of only 14.

It is one of the ironies of the campaign that the Brexiteers bang on constantly about Parliament’s loss of sovereignty and claim all our laws are made in Brussels.

It is a lie because, as they may yet find out, the British Parliament has retained more than enough sovereignty to thwart their plans and ignore the referendum result.

The British Parliament is sovereign and it is accountable to the people — but through elections at which we choose those whom we want to represent us, not through referendums. To rub in the point, Members of Parliament are representatives, not delegates, the difference being they are there to decide what in their judgment is good for us and the country, not simply to do what we say.

That is why we do not have capital punishment, which was abolished in the Sixties although a clear majority of the population remained in favour of it. A civil war was fought and a king beheaded to establish that sovereignty; it is not something that can be set aside at the whim of a Boris.

The interesting thing is that the 650 members of the House of Commons are overwhelmingly in favour of staying in. How overwhelming? Well Brian Reading, for many years one of the team at Lombard Street Research, has done the sums and published them on the website of Omfif, the financial think-tank. He thinks the Conservatives are 50% for remain, 40% for out and 10% unknown.

EU referendum campaign - in pictures 34 show all EU referendum campaign - in pictures 1/34 Boris Johnson (left) kisses a wild salmon as he is shown around Billingsgate Fish Market in London with porter Greg Essex, uncle of TV presenter Joey Essex, on the final day of campaigning Stefan Rousseau/PA 2/34 A van displaying an advert saying 'Don't Wake Up With Nigel Next Friday' is driven through Westminster Jack Taylor/Getty Images 3/34 Michael Gove speaks alongside Priti Patel (left) and Kate Hoey at a Vote Leave campaign event at Old Billingsgate market, London Dominic Lipinski/PA 4/34 A passenger on a train reads the Evening Standard on the London Underground EPA 5/34 Delia Smith during the Channel 4 EU referendum debate Dominic Lipinski/PA 6/34 David Cameron appears on a special referendum edition of BBC One's Question Time, hosted by David Dimbleby Stefan Rousseau/PA 7/34 Jayne-Anne Gadhia, CEO of Virgin Money, speaks to Sir Richard Branson about his views on the EU referendum Ben Pruchnie/PA 8/34 JD Wetherspoon beer mats that have been printed by the pub chain with strong messages in favour of leaving the EU JD Wetherspoon/PA 9/34 Ukip leader Nigel Farage and Kate Hoey on board a boat taking part in a Fishing for Leave pro-Brexit "flotilla" on the River Thames Stefan Rousseau/PA 10/34 Liberal Democrats leader Tim Farron greets supporters after arriving in the Liberal Democrat Vote Remain campaign bus in east London Ben Stansall/AFP/Getty Images 11/34 Boris Johnson MP visits Sam Cole Foods fish processing factory in Lowestoft, Suffolk, where he was campaigning on behalf of the Vote Leave EU campaign Stefan Rousseau/PA 12/34 A boat carrying supporters for the Remain in the EU campaign, including Sir Bob Geldoff, shout and wave at Brexit fishing boats as they sail up the Thames Ben Stansall/AFP/Getty Images 13/34 Yvette Cooper MP gives a helping hand to her husband and former shadow chancellor Ed Balls, as he gets up from a story time session, during a Vote Remain canvassing visit to Shadsworth Children's Centre in Blackburn. Christopher Furlong/Getty Images 14/34 The Sun backs Brexit Daniel Sotrabji/AFP Getty Images 15/34 Eddie Izzard campaigns for the Labour In campaign for the EU referendum Christopher Furlong/Getty Images 16/34 Leader of the United Kingdom Independence Party (UKIP) Nigel Farage poses with the party's new EU referendum poster in Westminster Jack Taylor/Getty Images 17/34 CBI director general Carolyn Fairbairn, Rohan Silva, Chuka Umunna, Sarah Sands, Munira Mirza and MEP Daniel Hannan at the Evening Standard Brexit Debate Nigel Howard 18/34 The Vote Leave campaign bus passes a Vote Remain poster featuring Nigel Farage and Boris Johnson as it arrives for a visit to clothing and uniform manufacturers Simon Jersey in Accrington, Lancashire Stefan Rousseau/PA 19/34 David Cameron makes a joint appearance with Mayor of London Sadiq Khan as they launch the Britain Stronger in Europe guarantee card at Roehampton University Yui Mok/Getty Image 20/34 Prime Minister David Cameron recreates the famous Beatles Abbey Road album cover by walking across Abbey Road crossing with Tessa Jowell, former secretary of state for culture, media and sport, on May 20, 2016 in London, England. The Prime Minister is campaigning to 'Remain' in the European Union ahead of a referendum on June 23 to decide on whether or not to leave the European Union Jeremy Selwyn 21/34 Leader of the United Kingdom Independence Party (UKIP) Nigel Farage holds aloft a UK Passport as he speaks during an anti-EU campaign event in Birmingham AFP/Getty Images 22/34 Campaigners wear clothing bearing the slogans "I'm Turning My Back On The EU", and "I Want To Leave The European Union, Do You?" as they attend a an Anti-EU (European Union) United Kingdom Independence Party (UKIP) pro-Brexit campaign event, in Birmingham Paul Ellis/AFP/Getty Image 23/34 A British national receives her postal ballot paper AFP/Getty Images 24/34 Boris Johnson MP takes to the wicket during a visit to Chester-Le-Street Cricket Club as part of the Brexit tour Ian Forsyth/Getty Images 25/34 A campaigner with the pro-Europe campaign group called 'Irish4Europe', hands out leaflets to visitors to the London vs Mayo Gaelic Athletic Association (GAA) football game at Ruislip GAA grounds in Ruislip, northwest London AFP/Getty Images 26/34 Labour Leader Jeremy Corbyn and former leader Ed Miliband (L) address supporters and members of the public in Doncaster town centre on May 27, 2016 in Doncaster, England. The Labour In campaign battle bus arrived in Doncaster today with Labour leader Jeremy Corbyn and Ed Miliband MP to canvass for votes and hope to persuade UK citizens to stay in the European Union when they vote in the EU Referendum on the June 23 Christopher Furlong/Getty Images 27/34 Secretary of State for Justice, Michael Gove, leaves after attending a cabinet meeting at 10 Downing Street Carl Court/Getty Images 28/34 A Vote to Leave campaigner holds a placard as Leader of the United Kingdom Independence Party (UKIP) Christopher Furlong/Getty Images 29/34 The image of a sari-clad Asian woman exactly balanced on a see-saw with a shaven-headed "thug" was devised by advertising giant Saatchi and Saatchi for the Operation Black Vote campaign. OBV said the poster - which features the slogan "A vote is a vote" and is due to be displayed on 37 digital billboards in London and Manchester - highlighted the "demonisation of foreigners and people of colour" in the campaign 30/34 Two pumps of Fuller's London Pride are branded with 'IN' and 'OUT' labels in the Red Lion Pub in Westminster Dan Kitwood/Getty Images 31/34 People walk past a graffiti mural of Donald Trump and Boris Johnson kissing, which is sprayed on a disused building in the Stokes Croft area of Bristol. The image, called 'The Kiss of Death' and painted by pro-EU campaign group We Are Europe, highlights the upcoming deadline for voter registration for the referendum on 7th June Ben Birchall/PA 32/34 The front page of The Sun newspaper on 9th March The Sun 33/34 London Mayor Boris Johnson addresses supporters during a rally for the 'Vote Leave' campaign on April 15, 2016 in Manchester, England. Boris Johnson is taking part in a 48 hour 'Brexit Blitz' of campaigning in Northern England. Britain will vote either to leave or remain in the EU in a referendum on June 23 Christopher Furlong/Getty Images 34/34 John Whittingdale, Theresa Villiers, Michael Gove, Chris Grayling, Iain Duncan Smith and Priti Patel attend the launch of the Vote Leave campaign at the group's headquarters in London Stefan Rousseau/Getty Images 1/34 Boris Johnson (left) kisses a wild salmon as he is shown around Billingsgate Fish Market in London with porter Greg Essex, uncle of TV presenter Joey Essex, on the final day of campaigning Stefan Rousseau/PA 2/34 A van displaying an advert saying 'Don't Wake Up With Nigel Next Friday' is driven through Westminster Jack Taylor/Getty Images 3/34 Michael Gove speaks alongside Priti Patel (left) and Kate Hoey at a Vote Leave campaign event at Old Billingsgate market, London Dominic Lipinski/PA 4/34 A passenger on a train reads the Evening Standard on the London Underground EPA 5/34 Delia Smith during the Channel 4 EU referendum debate Dominic Lipinski/PA 6/34 David Cameron appears on a special referendum edition of BBC One's Question Time, hosted by David Dimbleby Stefan Rousseau/PA 7/34 Jayne-Anne Gadhia, CEO of Virgin Money, speaks to Sir Richard Branson about his views on the EU referendum Ben Pruchnie/PA 8/34 JD Wetherspoon beer mats that have been printed by the pub chain with strong messages in favour of leaving the EU JD Wetherspoon/PA 9/34 Ukip leader Nigel Farage and Kate Hoey on board a boat taking part in a Fishing for Leave pro-Brexit "flotilla" on the River Thames Stefan Rousseau/PA 10/34 Liberal Democrats leader Tim Farron greets supporters after arriving in the Liberal Democrat Vote Remain campaign bus in east London Ben Stansall/AFP/Getty Images 11/34 Boris Johnson MP visits Sam Cole Foods fish processing factory in Lowestoft, Suffolk, where he was campaigning on behalf of the Vote Leave EU campaign Stefan Rousseau/PA 12/34 A boat carrying supporters for the Remain in the EU campaign, including Sir Bob Geldoff, shout and wave at Brexit fishing boats as they sail up the Thames Ben Stansall/AFP/Getty Images 13/34 Yvette Cooper MP gives a helping hand to her husband and former shadow chancellor Ed Balls, as he gets up from a story time session, during a Vote Remain canvassing visit to Shadsworth Children's Centre in Blackburn. Christopher Furlong/Getty Images 14/34 The Sun backs Brexit Daniel Sotrabji/AFP Getty Images 15/34 Eddie Izzard campaigns for the Labour In campaign for the EU referendum Christopher Furlong/Getty Images 16/34 Leader of the United Kingdom Independence Party (UKIP) Nigel Farage poses with the party's new EU referendum poster in Westminster Jack Taylor/Getty Images 17/34 CBI director general Carolyn Fairbairn, Rohan Silva, Chuka Umunna, Sarah Sands, Munira Mirza and MEP Daniel Hannan at the Evening Standard Brexit Debate Nigel Howard 18/34 The Vote Leave campaign bus passes a Vote Remain poster featuring Nigel Farage and Boris Johnson as it arrives for a visit to clothing and uniform manufacturers Simon Jersey in Accrington, Lancashire Stefan Rousseau/PA 19/34 David Cameron makes a joint appearance with Mayor of London Sadiq Khan as they launch the Britain Stronger in Europe guarantee card at Roehampton University Yui Mok/Getty Image 20/34 Prime Minister David Cameron recreates the famous Beatles Abbey Road album cover by walking across Abbey Road crossing with Tessa Jowell, former secretary of state for culture, media and sport, on May 20, 2016 in London, England. The Prime Minister is campaigning to 'Remain' in the European Union ahead of a referendum on June 23 to decide on whether or not to leave the European Union Jeremy Selwyn 21/34 Leader of the United Kingdom Independence Party (UKIP) Nigel Farage holds aloft a UK Passport as he speaks during an anti-EU campaign event in Birmingham AFP/Getty Images 22/34 Campaigners wear clothing bearing the slogans "I'm Turning My Back On The EU", and "I Want To Leave The European Union, Do You?" as they attend a an Anti-EU (European Union) United Kingdom Independence Party (UKIP) pro-Brexit campaign event, in Birmingham Paul Ellis/AFP/Getty Image 23/34 A British national receives her postal ballot paper AFP/Getty Images 24/34 Boris Johnson MP takes to the wicket during a visit to Chester-Le-Street Cricket Club as part of the Brexit tour Ian Forsyth/Getty Images 25/34 A campaigner with the pro-Europe campaign group called 'Irish4Europe', hands out leaflets to visitors to the London vs Mayo Gaelic Athletic Association (GAA) football game at Ruislip GAA grounds in Ruislip, northwest London AFP/Getty Images 26/34 Labour Leader Jeremy Corbyn and former leader Ed Miliband (L) address supporters and members of the public in Doncaster town centre on May 27, 2016 in Doncaster, England. The Labour In campaign battle bus arrived in Doncaster today with Labour leader Jeremy Corbyn and Ed Miliband MP to canvass for votes and hope to persuade UK citizens to stay in the European Union when they vote in the EU Referendum on the June 23 Christopher Furlong/Getty Images 27/34 Secretary of State for Justice, Michael Gove, leaves after attending a cabinet meeting at 10 Downing Street Carl Court/Getty Images 28/34 A Vote to Leave campaigner holds a placard as Leader of the United Kingdom Independence Party (UKIP) Christopher Furlong/Getty Images 29/34 The image of a sari-clad Asian woman exactly balanced on a see-saw with a shaven-headed "thug" was devised by advertising giant Saatchi and Saatchi for the Operation Black Vote campaign. OBV said the poster - which features the slogan "A vote is a vote" and is due to be displayed on 37 digital billboards in London and Manchester - highlighted the "demonisation of foreigners and people of colour" in the campaign 30/34 Two pumps of Fuller's London Pride are branded with 'IN' and 'OUT' labels in the Red Lion Pub in Westminster Dan Kitwood/Getty Images 31/34 People walk past a graffiti mural of Donald Trump and Boris Johnson kissing, which is sprayed on a disused building in the Stokes Croft area of Bristol. The image, called 'The Kiss of Death' and painted by pro-EU campaign group We Are Europe, highlights the upcoming deadline for voter registration for the referendum on 7th June Ben Birchall/PA 32/34 The front page of The Sun newspaper on 9th March The Sun 33/34 London Mayor Boris Johnson addresses supporters during a rally for the 'Vote Leave' campaign on April 15, 2016 in Manchester, England. Boris Johnson is taking part in a 48 hour 'Brexit Blitz' of campaigning in Northern England. Britain will vote either to leave or remain in the EU in a referendum on June 23 Christopher Furlong/Getty Images 34/34 John Whittingdale, Theresa Villiers, Michael Gove, Chris Grayling, Iain Duncan Smith and Priti Patel attend the launch of the Vote Leave campaign at the group's headquarters in London Stefan Rousseau/Getty Images

On the Labour side, remain is supported by 215 members, leave by seven and there are 10 unknown. In percentage terms, that makes 93% in favour of staying, against 3% for leaving.

The 56 Scottish Nationalists and the eight Liberals are overwhelmingly for remain but the views of the Welsh and Northern Irish members are more mixed. Nevertheless, the overall picture is clear. Reading concludes that the MPs are 70% in favour of remaining with 20% wanting to leave and 10% whose preferences are unknown. That does not sound far off the mark.

So what will Parliament do in the event of a referendum vote for Brexit? Reading suggests it will depend very much on the size of the majority and the turnout. If the vote was 60 to 40 to leave on a turnout of 80%, MPs might feel obliged to support a Bill for exiting because there was so much popular support.

But if the vote was 51 to 49 on a turnout of 50%, they could legitimately argue that only just over 25% of the population had actively supported Brexit, and supporting a Bill to leave would be too big a step to take on the basis of such thin support. So, even if he wanted to, David Cameron could not get such a bill through the Commons, let alone the Lords. Prime Minister Boris Johnson, if he were to topple Cameron, would have even less chance.

So how might this be resolved? One obvious tactic would be for Cameron to accept the Brexit vote and undertake to begin negotiations for withdrawal without actually triggering the formal mechanism that sets the two-year clock ticking. As these negotiations proceed, people will gradually get a better idea of what Brexit might mean in practice and it is a fair bet if the negotiations are tough that they might begin to have some doubts as to what they had signed up to.

Even if they like the romantic idea of swimming in the wide open sea, they might not want to jump off Beachy Head to get into the water.

Once there was a clear idea of what leaving would look like, it might be legitimate to go back to the country and ask, via another referendum, whether people still wanted to do this. And who knows what that result would be.

Perhaps the only real conclusion is that, far from settling the issue, this referendum is most likely to make things worse. A Remain vote is not going to convince the Tories that they should work more constructively and enthusiastically with the EU; a Leave vote may not achieve that result either. These past few weeks have entrenched prejudices far more than they have opened minds.