Is a second referendum now on the cards?

Theresa May is talking about a second referendum today; she will tell MPs that it would do "irreparable damage" to our democracy.

As the prime minister faces incoming fire over her return from Brussels last week empty-handed, and the clock ticking down to exit day without an apparent plan B, does she protest too much about another vote?

It is certainly a sign of how the so-called "People's Vote" has gained currency in the past couple of weeks, that arguing against it as a way to break the deadlock is the prime minister's main message coming out of the failed summit.

Weeks ago only a marginal issue, now dozens of Labour MPs are backing another vote, as well as the SNP, Liberal Democrats, and smaller parties.

But the real battle is, of course, for Conservative support, otherwise it's not a runner.

:: What are the next options for Brexit?

Only around ten Tory MPs have publicly stated their support for a second vote, but I'm told that a sizeable group of Europhile ministers and MPs are waiting in the wings to see if it emerges as the most likely option and would, with various degrees of reluctance, eventually give it their backing.

Many of them have deep doubts about how it would work, what the question would be, how to address the claim that it is a betrayal of the result in 2016, and crucially, whether the outcome would be any different.

But if no other option can command a majority in parliament, they believe it is swiftly becoming a likely outcome and feel confident that some in cabinet share their views.

Sam Gyimah, the universities minister who resigned his post in protest at Theresa May's Brexit deal last month, says he has discussed a second referendum with cabinet ministers.

He articulated the concerns of many Tories in a brutal tweet last night, warning that the prime minister may leave parliament staring down the barrel of no deal by running down the clock.

Downing St has stopped selling the PMs flawed deal. Instead we have displacement activity designed to distract from last weeks failed renegotiation. And a concerted attempt to discredit every plausible alternative as they run down the clock. This is not in the national interest.

— Sam Gyimah MP (@SamGyimah) December 17, 2018

With little immediate sign of how Mrs May can secure the required concessions from Brussels to win parliamentary support for her deal, two of the prime minister's senior allies were yesterday forced to deny they were planning for a second vote.

Is it on the cards? For supporters of the idea, there are huge obstacles to making a second referendum happen.

Legislation would need to pass Parliament, and currently neither the government nor Labour currently support it.

There is also the question of time - it took seven months to get the legislation through for the 2016 poll, and extending Article 50 would undoubtedly be required.

Many MPs, both Labour and Conservative, are deeply nervous about the cries of betrayal which could flow from it.

If "Remain" is an option, they point out that it could win, but on a lower turnout than in 2016.

The question asked would also be highly contested.

One senior member of the shadow cabinet, who is currently withholding support for the idea, has warned colleagues against putting the option of "no deal" to the public and making that into the default Brexit option.

What has the potential to swing the dial is that members of the cabinet are now publicly advocating free votes in parliament, to test the levels of support for different options - including a second referendum.

The idea, raised on the cabinet's conference call last Monday, was knocked back by the prime minister, who, I'm told, said it would lead to "game playing in parliament."

But yesterday the Brexiteer International Trade Secretary Liam Fox, Education Secretary Damian Hinds and this morning both Amber Rudd and the Business Secretary Greg Clark all backed the idea.

Mrs May, a Downing Street source confirms to me today, is still not keen.

But it is difficult for a prime minister with limited support in her party, to argue against giving parliament the final say.

To most of her enemies on her backbenches and her coalition partners the DUP, a second referendum, and possibility of thwarting Brexit, is the worst of all worlds.

If there is any way through the impasse, the prime minister, talking up the risks of a second referendum, can only hope that her best chance of eventually getting a deal through parliament is that Brexiteers will fear leaving the EU slipping from their grasp.