An expert on why Prime Minister Theresa May is struggling to sell the Brexit deal to the UK Parliament and the public.

British Prime Minister Theresa May and European Union leaders signed off on a Brexit plan on Sunday, which will dictate the terms of the divorce between the European Union and the United Kingdom.

Now May needs to sell the deal at home, and persuade members of the UK Parliament to back the agreement for a vote in early December. There’s just one problem: Most of the United Kingdom seems to despise the plan.

The debate over how the UK and the EU should split up has exposed deep and intractable fault lines in British politics. The June 2016 referendum, in which 52 percent of the UK voted to leave the European Union, exposed schisms that will likely last long after the official Brexit deadline of March 29, 2019.

To better understand the contours of the current debate, I reached out to Anand Menon, the director of an independent Brexit research institute called UK in a Changing Europe and a professor at King’s College in London. He’s also the co-author of the book Brexit and British Politics.

We discussed the current polarization over the Brexit, and why it doesn’t break down neatly along the traditional political lines of the Conservative or Labour parties. He also discussed the challenges that May faces as she tries to convince her Conservative Party and the rest of Parliament to support the agreement.

Our conversation, which has been condensed and edited for clarity, follows.

Jen Kirby

Can you put the current debate over the Brexit plan into context?

Anand Menon

The [Brexit] deal is almost a cipher for a completely different debate. We’re still, in a sense, fighting the referendum.

One side in Parliament is focused on defeating the deal, because they don’t know if any deal is as good as [EU] membership. They see this as a proxy for getting to a second referendum.

Then there’s the other side. Some of them have always wanted to leave the European Union without worrying about a trade deal. There is no deal that could have satisfied this group, and they’re anxious to vote it down because their aspiration is that we leave with no deal.

There are also other Tory MPs who want some kind of deal but would rather have no deal than the deal that is being offered.

The middle ground in Parliament is disappearing, and we’re seeing these two rival camps who are sworn enemies walking through the lobbies together because they see the chaos that would ensue from the deal being defeated as being the route to their preferred outcome.

Jen Kirby

Crashing out of the EU without a deal seems like it could be really disastrous. Why take the risk?

Anand Menon

There are proponents of chaos on both sides of the divide — on the far left and the far right. They think that the UK leaving the EU with no Brexit deal will create the chaos necessary for the kind of radical reform this country needs.

It’s not a very easy thing to say out loud, so they don’t tend to say it out loud. They tend to say, “It will be fine, don’t worry about it,” or, “The implications of no deal are being exaggerated.” What you never know when you’re talking to people in this debate is whether they actually mean what they say or they’re saying it for tactical reasons.

Jen Kirby

So is anyone in the UK Parliament enthusiastic about the deal that May and the EU have put forward?

Anand Menon

Because we are polarized into “Remain” and “Leave” camps in this country, no one thinks this is perfect or ideal. There are some people who are willing to go along with it, but as I said, there are a lot of people who are using this as a proxy for something else.

What we don’t know is whether or not this will change as we approach the actual vote around December 11 or 12. The initial reaction to the text was hostile, but the campaigning begins now.

That’s going to take several forms. The prime minister is going to go around the country campaigning to ordinary people about it. It will also doubtless take the form of the odd intervention from people from the European Union saying this is the only deal on offer.

The rumors are, [May] is going to try to get foreign leaders, like the Japanese prime minister, to come out and say this is good. We’ll just have to see how it goes. There’s no doubt that it will be a very, very hard task to get this through Parliament at the moment.

Jen Kirby

And what about all this talk of a second referendum? How realistic is it?

Anand Menon

One of the very curious things about British politics as it stands now is we face one of a number of very implausible outcomes. We might have an election. We might have a referendum. We might have no deal. The prime minister’s deal might be accepted.

They’re all massively implausible, okay? But what we know is that one of them is going to happen. That’s what makes things in Britain so odd.

Of course, you could get a referendum. It will be very, very hard because you would need government to move a bill to say there is a referendum. So it could be that some amorphous gathering of backbench MPs vote in favor of a referendum, and that’s enough to force a government to put a motion through.

Remember, the last local elections we had, the calculation was around 70 percent of Conservative voters were “leavers.” So for a Conservative government to preside over a [second] referendum that voted to remain, which it may not, but hypothetically could, would be incredibly damaging for the Conservative brand.

So it’s very hard to see circumstances in which the government would let this happen. But it might. The polling is close, and we’re uncertain about how such a referendum would go. It would be incredibly divisive.

Jen Kirby

It’s been hard to pin down the Labour Party’s position on Brexit. They’ve seemed pretty ambivalent about it.

Anand Menon

As the opposition, that’s an ability you have: You don’t have to be as specific as the government does. But I do wonder, as we go toward this parliamentary vote and Labour keeps saying, “We are going to vote against the government’s deal,” whether the media might push them into saying, “Okay, you’re going to vote against the deal. What sort of deal would you accept?”

There are huge contradictions in Labour’s policies. What Labour seems to be promising is something that the European Union simply won’t give — ending free movement of people but having a very good relationship with the single market, being inside a customs union with the EU but still being allowed to have a say over EU trade deals. None of that is on the table as far as the EU is concerned.

Jen Kirby

Does part of the opposition to this Brexit deal come down to the fact that Brexiteers who promoted leaving the European Union made promises that they ultimately couldn’t keep, or didn’t hold up to reality?

Anand Menon

The Leave campaign was all things to all men.

Some people voted to leave for contradictory reasons. One of the things the Leave camp did very, very well was it harnessed dissatisfaction with the political elite, with the politics of austerity, and those people voted to leave because they saw it as a way of getting more money for public services.

There are Conservative leavers who see Brexit as a way of shrinking the state still further. So you can’t find a solution that’s gonna please every Leaver.

That’s one of the big problems in Britain at the moment. A lot of falsehoods were spouted during the referendum, but here we are now, and the problem is there isn’t a majority for any outcome.

That’s why, in a sense, the pain of Parliament is understandable. It’s the pain of the people. We don’t have a stable majority for any outcome.

Jen Kirby

What is the public perception of the Brexit debate?

Anand Menon

The public are divided down the middle. One of the reasons they’re divided down the middle — and this is not dissimilar to the US — is because Brexit has activated a values divide.

This isn’t a traditional left-right thing. This is almost our equivalent to a culture war. If you want to predict how people voted, it’s their views on diversity, on gay rights, on gender equality, on the death penalty. It’s those values issues that people are coalescing around.

What we know about those issues is once they’ve been ignited in political debate, they’re very hard to put out again. People hold those beliefs very deeply and find it hard to change them. That’s one of the reasons why people aren’t changing their minds. It’s one of the reasons why the Brexit division is proving to be a very deep division indeed. A majority of British people now identify themselves as Leaver or Remainer rather than Labour or Tory.

At the same time, no one has a huge amount of faith in any of our political leaders because the perception is that both Theresa May and [Labour Party leader] Jeremy Corbyn just aren’t very competent at their jobs.

Finally, one of the reasons this is messy is because we have a series of crises going on at the same time, all of which, except Brexit, were brewing before the referendum, and all of which have been made worse by the referendum.

We’ve got a crisis of economics because of high levels of inequality and an enormous amount of economic pain being placed upon those least able to deal with it through austerity. We’ve got a crisis of trust in politics that I suppose goes back to Iraq, was made far worse by the MPs expenses scandal, wasn’t helped by the coalition government, and was one of the reasons why people voted to leave.

We have a constitutional crisis brewing in Scotland that was brewing before the referendum because of their referendum on independence. And even before the Brexit referendum, there was a crisis brewing in Northern Ireland. It’s been made far worse because of Brexit.

There are all these different crises swirling around at the same time. They’ve all been made worse by Brexit, but they haven’t been caused by Brexit, necessarily. That’s one of the reasons this is proving so intractable.

Jen Kirby

This division: What does it mean for the future of British politics?

Anand Menon

Oh, god. I have no clue. It is very hard to see what’s going to happen in the next two or three weeks, let alone what’s going to happen in the next two or three or 10 years. This is a defining event in British politics. I think we are in for some very rocky years ahead.