BRUSSELS (Reuters) - “Trust me,” Prime Minister Theresa May told other European Union leaders on Thursday, saying that with their help, she could win the British parliament’s backing for her Brexit deal and prevent a chaotic departure.

British Prime Minister Theresa May arrives at a European Union leaders summit in Brussels, Belgium December 13, 2018. REUTERS/Piroschka van de Wouw

A day after a failed attempt to oust her by lawmakers in the governing Conservative Party, May told leaders of the other 27 EU members she believed there was majority in parliament for her Brexit deal, she just needed a little more from them.

May postponed a parliamentary vote on the deal this week for fear of suffering a resounding defeat and is asking the EU to help her find a way to break the deadlock over Brexit, Britain’s biggest shift in trade and foreign policy for more than 40 years.

Asking for political and legal assurances that the so-called Northern Irish backstop would be temporary, May urged the leaders to look at her track record of delivering results even when the odds looked stacked against her.

“Over the last two years, I hope I have shown that you can trust me to do what is right, not always what is easy, however difficult that might be for me politically,” she said, according to a senior British official.

Earlier, French President Emmanuel Macron said the legal agreement could not be reopened, adding: “We can’t renegotiate what was negotiated for several months.”

May said she believed there was “a majority in parliament who want to follow through on the referendum and leave with a negotiated deal” but asked for help in changing the perception that the backstop arrangement was a trap.

“I am in no doubt the best result for all of us is to get this deal delivered in an orderly way and to get it done now. It is in none of our interests to run the risk of an accidental no deal (exit) with all the disruption that would bring, or to allow this to drag on any further.”

With less than four months before Britain is due to leave on March 29, May’s deal agreed with the EU last month has only hardened positions at home, throwing up more uncertainty for businesses trying to predict what will happen next.

Scenarios range from Britain leaving without a deal to no Brexit at all, but May said all the uncertainty could come to an end if she secured the additional assurances -- including measures that have legal force -- on the backstop.

The backstop aims to ensure there is no return to controls on the border between the British province of Northern Ireland and the Irish Republic. However, it is the main stumbling block for lawmakers in London who fear Britain will become stuck in the fallback arrangement, hindering trade deals beyond the EU.

“We have to change the perception that the backstop could be a trap from which the UK could not escape. Until we do, the deal, our deal, is at risk,” she said.

“There is a majority in my parliament who want to leave with a deal so with the right assurances this deal can be passed, indeed it is the only deal that is capable of getting through my parliament.”