Theresa May faces a dilemma as she heads into the most crucial period of her premiership | Jack Taylor/Getty Images Exclusive Poll Most British voters want Brexit compromise, but Tories don’t New poll for POLITICO highlights Theresa May’s domestic dilemma.

LONDON — The U.K. is ready to compromise on Brexit. Conservative voters are not.

That's Theresa May’s dilemma as she heads into the most crucial period of her premiership, with the Brexit negotiations hanging by a thread.

Britain and the EU must find a breakthrough on the Irish border issue — the main sticking point in the talks — before the end of next week to clinch a special summit of EU leaders in mid-November to sign off on a final Brexit agreement. If that doesn't happen, the chances of a messy no-deal divorce increase dramatically, leaving a last-gasp December summit as the last realistic chance to salvage a deal.

As the pressure on the prime minister mounts, the results of an exclusive poll for POLITICO by the consultancy Hanbury Strategy show that while the public as a whole wants decision-making powers returned to Westminster after Brexit — rather than accepting "rule taker" status — it opposes leaving without a deal and supports compromises being made to reach an agreement.

Despite apparent public willingness to compromise to reach an acceptable agreement with Brussels, the views of Conservative voters are much more hard-line.

According to the poll of 3,006 voters carried out between Monday and Friday, the public is so set against "no deal" it would prefer to remain in the EU than leave without a divorce agreement. By 53 percent to 47 percent, voters say they would prefer Britain stayed in the EU than leave without a deal.

The result is likely to spark further calls from anti-Brexit campaigners for a so-called People’s Vote on the terms of Britain’s EU divorce, with the option of remaining in the bloc on the ballot paper.

By 47 percent to 35 percent, voters also want the U.K. prime minister to “compromise” with the EU to get a deal, rather than walk away without one in March.

Voters break narrowly (39 percent to 38 percent) against extending the transition period — during which the U.K. will accept EU rules and regulations without a say in making them — if it costs "billions" of pounds a year to do so.

But 59 percent of voters say they would accept a transition extension when cost is stripped out of the equation, suggesting any delay in getting out of the transition will need to be carefully sold to the electorate to avoid a backlash — because the EU has made clear the U.K. will not be able to retain the benefits of the single market and customs union for free.

Despite apparent public willingness to compromise to reach an acceptable agreement with Brussels, the views of Conservative voters are much more hard-line, posing a major strategic headache for the prime minister.

Overall, 48 percent of those who voted Conservative in the 2017 election who took part in the survey would prefer May walking away without a deal to a compromise, compared to 41 percent who would prefer her to compromise.

Tory tribes

Following the Brexit referendum in 2016 — and the subsequent collapse in support for UKIP in favor of the Conservative Party — the bulk of Tory voters can now be defined as either “loyal Tory leavers” or “switching Tory leavers.”

The first group are those who have voted Conservative in each of the past two elections and voted to leave the EU. The switchers are those who backed May at the last election after voting Leave in 2016, even though they previously supported either UKIP or Labour or did not vote.

In these groups — which make up over 65 percent of the Tory vote — the willingness to compromise to reach a deal with Brussels is far less obvious.

Just 25 percent of 2017 Conservative voters support Theresa May's Chequers Brexit plan compared with 56 percent who support a so-called Canada deal and 19 percent who support the so-called Norway option.

Furthermore, six in 10 “loyal Tory Leavers” and 65 percent of "switching Tory leavers" favor May walking away without a deal over making further compromises.

The poll reveals the Conservative Party’s electoral dilemma as it faces up to a Labour opposition that has offered tentative support for Britain’s withdrawal from the EU, but on much softer terms than the Tories, and is just about holding together its own fragile coalition of Leavers and Remainers.

For the Conservative Party, the problem is more acute — because they are in power and Labour is not.

Of the 50 most marginal Tory seats in parliament and its 50 top target seats, according to Hanbury, 51 are Leave-backing constituencies, which voted for Brexit by more than 55 percent. In comparison, just 22 seats voted Remain by more than 55 percent.

Of 2017 Conservative voters in these 100 key seats, 45 percent think that May should walk away without a deal, compared with 37 percent who think that she should compromise — almost the exact reverse as the country as a whole.

Overall, 60 percent of these key voters support a Canada-style deal with the EU compared to 21 percent who support a Chequers-like arrangement and 19 percent who support the "Norway plus" option.

British voters would prefer to have the power to strike independent trade deals even if doing so means a hard border in Ireland.

When presented with the basic outlines of the three main Brexit propositions without their usual shorthand titles — either a Canada-style free-trade deal, a Norway-plus single market and customs union option, or the prime minister’s halfway-house Chequers proposal — the country as a whole also prefers “Canada.”

Four in 10 voters would prefer such a looser trade deal to a single market-type relationship. Three in 10 support “Norway” and 29 percent back Chequers.

When asked whether they would prefer to be in control of immigration or keep close economic ties with Europe, immigration wins by 60 percent to 40 percent.

Some 65 percent of voters value “more flexibility” for the U.K. to set its own laws and regulations over 35 percent who prefer “more investment and trade with the European Union."

Even starker, British voters would prefer (by 59 percent to 41 percent) to have the power to strike independent trade deals even if doing so means a hard border in Ireland.