Up hill and down dale, Theresa May is trekking assiduously across the nation trying to sell her Brexit deal.

In short her tactic is: If you lot want Brexit this is the only option.

Her thinking is if the public get behind it then the MPs who she actually needs to back it will have no choice than to vote it through on December 11.

Even if that plan garners some traction this is going to be a very tight vote.

Labour will vote against it.

The DUP will vote against it.

The Liberal Democrats will vote against.

The SNP will vote against it.

And scores of Tories will also vote against it.

The odds appear to be stacked against the prime minister.

But there are some signs of softening. Brexiteer and leader of the House of Commons Andrea Leadsom is behind Mrs May's deal. Michael Gove, another prominent Leaver, is standing by the PM. And even arch-Europhile and Tory grandee Ken Clarke is, perhaps reluctantly, going to vote in favour of the agreement.

But it is still going to be a huge uphill battle.

People from all sides agree the deal is deeply flawed. This increasingly feels like a choice between the devil and the deep blue sea.

With every passing day there appears to be more warnings about the chaos that lies ahead if the UK cannot secure a deal before March 29. Many Brexiteers have dismissed these forecasts as Project Fear 2.0 in reference to the negative campaign Remain ran during the referendum.

But there is obvious concern.

And what warnings like those delivered by the Bank of England this week will do is get MPs thinking long and hard about the moment they go through the voting lobby at the end of the debate on the Brexit deal.

They may well hate the deal. Many will wish they could turn back time and re-run the referendum with a different outcome, and some will be Leavers whose red lines have been crossed by Mrs May's agreement.

But if the Bank of England is right and a no-deal would send the economy into a tailspin, hit house prices by a whopping 30% and see unemployment rates spike, no MP is going to want to have to face struggling constituents and say 'yep ... I voted for that'.

Some, of course, are Brexit zealots who are completely convinced that a hard exit would actually be better for the country. My economics is not bad but I wouldn't like to predict the impact of Brexit. Forecasting before the referendum had all hell breaking loose on June 24, 2016, if we left. Yes, the pound suffered but we are not enduring a Mad Max-type dystopia.

Change though is tough. It usually hurts even if only in the short term. Is the threat of that change, and therefore pain, enough to change the minds of the majority of MPs? It is all still to play for.

Mrs May believes her deal is the only way to break the impasse. She is wrong though. Something else is looming on the political horizon, a choice that could blow the whole debate wide open again. And the Brexiteers are worried.

The shadow chancellor – who is, I am informed, not getting along as well as he once did with Labour's leader – this week called a People's Vote 'inevitable' if his party can't force a general election which seems unlikely.

So far Jeremy Corbyn – who has long-held Eurosceptic views – has said Labour cannot reverse the decision. But imagine if, during that planned television debate, he dropped a bombshell and said he would back one in a bid to break the deadlock?

It might be his last hope. Labour were convinced there would be another general election before Brexit, they thought they were going to get another go at Mrs May's Tories. Even at Labour conference a confident Emily Thornberry, the shadow foreign secretary, told me they were working towards a November election.

Labour is running out of time. Perhaps a second referendum is Mr Corbyn's last chance?