Today the postponement of a debate on an anti-Brexit petition was announced. The rules are that all e-petitions on parliament.uk reaching 100,000 signatures must be given a Commons debate. No guarantees, but at least we hear the government’s arguments. This one, calling for the autumn debate on the final Brexit deal to include the option to remain, reached the name total before Easter and a debate was duly scheduled.

And then rescheduled for the end of April… and then rescheduled for June 11th. The government does not want this debate. It does not want MPs to have options beyond either accepting the deal or exiting without a deal. It certainly does not want the people to have a vote on the deal, and it is adamant there will be not be another referendum. Democracy happened on June 23rd 2016, and there will be no more votes of the people on Brexit.

The new People’s Vote campaign, launched on 15th April, sings from the same hymn sheet. This campaign – run out of the Millbank Tower – wants people to vote, but only on the terms of the deal. The decision to leave is sacrosanct and must be ‘respected’. The private briefing issued by Open Britain to supporters is clear – on the 2016 vote “this is not in any way about re-running it”. There must be no further popular votes on Brexit.

Hostility towards a popular vote on Brexit is growing, and it is starting to threaten Labour. While the opposition party has not entirely ruled out a third referendum – and it would be a third, Harold Wilson having run the first in 1975 and David Cameron the second in 2016 – current thinking around Starmer’s six tests is that if the government deal does not match them, Labour will vote against the deal. Yet it cannot vote down the deal unless Tory MPs join them in the division lobby. There is no sign that they are working to secure this, though Open Britain – headed by Chuka Ummuna and Anna Soubry – brings together Labour, Conservative and Liberal Democrat politicians. Labour has no principled objection to voting with the Tories, having voted with them on Article 50 and with some on the Withdrawal Bill amendments, but that was last year.

This year Labour is arguing among itself about Starmer’s six tests, with Emily Thornberry and others pointing out that the deal in autumn 2018 is not going to be the Real Deal. This is correct. The details will take years to finalise – Canada was worked out over seven years. Thornberry may have been flippant in calling the upcoming vote on the deal the “blah blah blah” choice, but she has a point. The actual heads of agreement which will be the only available option in the autumn will be almost impossible to vote against. Although the terms will be vague, the commitment to leave on March 29th will be clear.

While the Millbank Tendency believe defeating the bill would be delaying the issue, allowing Britain to remain in the EU for some time, May intends to take the UK out on March 29th. She will Brexit on World Trade Organisation rules, using Crown Prerogative and the mandate of the 2016 referendum. As Labour and the Millbank Tendency accepts the result of the 2016 referendum, they cannot oppose Britain leaving the EU next March.

While both the frontbench and the Millbankers think that rejecting the proposal could postpone leaving the EU while Britain and Europe haggle over the terms, this is unlikely. If the People’s Vote happens, the people are likely to approve the deal. Business certainly does not want a period of uncertainty. The country wants to know what is happening – business in particular wants to know whether to invest. Only among Millbank supporters is a delaying tactic an option.

For Labour, the issues are starker. If the party repeats its Article 50 actions and goes in with the Tories, it loses remain voters. If it votes for stopping the bill, it loses its leaver constituency. The pattern could be repeated across the UK – in Scotland, the SNP is for Remain, Tories for Leave. In Northern Ireland, DUP is for Leave, Sinn Fein for Remain. Labour is caught in no man’s land. And in the long term, if Brexit is successful, the Tories gain. If it is a disaster, Lib Dems gain. The only party that cannot gain is Labour. Sitting on the fence and making conditions that cannot be met is a blind alley.

There is a way out, and one that can regain the democratic card Theresa May now holds as the guardian of the 2016 vote. It is to call for a third referendum. One argument that Open Britain and the Millbankers have right is that the promises of 2016 are souring and people were not told the truth. No one said that the divorce bill involved paying £39bn pounds. Circumstances do alter cases – but MPs cannot over ride a referendum. If Labour is to regain the democratic argument that the Brexit vote debate postponement suggests the Tories do not want to have, it has to embrace putting the final decision on Brexit to a third referendum.

Trevor Fisher is a Labour member and a former member of the Labour Co-Ordinating Committee (LCC) executive, the Compass executive and the Rank and File Mobilising Committee (RFMC).