Britain’s embattled Theresa May will make a push this week to persuade rebel lawmakers in her ruling Conservative party to back her contentious Brexit withdrawal agreement.

But little has changed since she delayed before Christmas a House of Commons vote on the proposed deal and few observers believe she’ll be successful as many rebel lawmakers are locked into their opposition because of public promises they’ve made to their constituency parties.

Meanwhile, political pressure is mounting on the prime minister, who insists she can win the vote, to delay Britain’s scheduled March 29 exit from the European Union.  Two former ministers from the Cabinets of Margaret Thatcher, Ken Clarke and Chris Patten, have urged her to rethink and put Britain’s exit from the bloc on hold in order for a political consensus to be hammered out on Britain’s future relationship with the EU.

Patten added his voice Monday to calls for a re-run Brexit referendum, “It may be that we can only end this divisive and impoverishing argument by holding another referendum,” he said.

May has adamantly ruled out holding another plebiscite to break the parliamentary deadlock.  More than 200 MPs from various parties have signed a letter urging her to take the prospect of a no-deal Brexit off the table, if she fails to garner the parliamentary support she needs for her Brexit withdrawal agreement to be approved.

The politicians from the Conservative, Labor, Liberal Democrat and the nationalist parties of Scotland and Wales are concerned about the impact on British manufacturing crashing out of the bloc in March without any kind of arrangement with the European Union, the only legal current option.

In their collective letter, the lawmakers wrote, “Leaving the EU without a deal would cause unnecessary economic damage.  Trading on World Trade Organization terms would instantly make our manufacturers less competitive and make it very difficult for the industry to justify producing goods in the UK for export. Leaving without a deal would make continued investment in UK manufacturing a real challenge for global firms, when they have plants in other European locations.”

May has little more than a week to rescue her Brexit plan.  The House of Commons will restart debate on the Brexit withdrawal agreement Wednesday.

The House of Commons is likely to vote on the proposed deal next week unless the government again postpones it, something May on Sunday pledged not to do.

May’s deal, which was negotiated after almost two years of ill-tempered haggling between British and EU negotiators, tries to square the circle between Britons who want to remain in the EU, or closely tied to it, and Brexiters.

The proposed deal would see Britain locked in a customs union with the European Union for several years while it negotiates a more permanent, but vaguely defined, free-trade settlement with its largest trading partner.  In the temporary customs union, Britain would be unable to influence EU laws, regulations and product standards it would have to observe.  It would not be able to implement free trade deals with non-EU countries.

The transition was agreed to avoid customs checks on the border separating Northern Ireland and the Irish Republic, but British lawmakers fear Britain could be shackled indefinitely to the bloc even if a final free-trade deal isn’t negotiated.  Brexiters claim the Brexit agreement May negotiated turns Britain into a “vassal state,” a rule-taker and not a rule-maker.

May’s aides appear convinced the European Union will offer some concessions in the next few days to help the British leader get the votes she needs, but critics say they’re reaching for straws, and EU leaders frustrated with the time and energy they have spent on Brexit appear in no mood to offer her assistance.

Britain’s divorce deal with Brussels is the only deal on the table and cannot be renegotiated, an EU Commission spokesperson said Monday.  EU officials say the bloc will continue to advance its “no deal” planning and no more Brexit negotiation meetings are scheduled.  The language used by the EU Commission Monday is no different from what EU leaders have used since the deal was signed in November.

May promised before Christmas to get legal reassurances from Brussels over the so-called Irish backstop – the insurance policy to ensure a hard border with customs checks is not reimposed on the island of Ireland.

With May unable apparently to squeeze anything out of the bloc’s negotiators in the final hour that would substantially alter the political dynamic in London, her aides are also considering a parliamentary trick — to change the wording of the legislation presenting the Brexit withdrawal agreement next week by making any approval of the deal contingent on the European Union offering more concessions.

The move would be intended to limit the scale of the parliamentary rebellion against May. But EU officials say that would infuriate Brussels, which would unlikely accept the blackmail.