LONDON: (DNA) –  British lawmakers on Tuesday instructed Prime Minister Theresa May to reopen a Brexit treaty with the European Union to replace a controversial Irish border arrangement — and promptly received a flat rejection from Brussels.

Two weeks after overwhelmingly rejecting May’s Brexit deal, parliament backed a proposal intended to send her back to Brussels with a stronger mandate to seek changes that were more likely to win their support.

At the same time, they rejected a proposal to give parliament a path to prevent a potentially chaotic ‘no-deal’ exit by making May ask Brussels for a delay if she cannot get a deal through parliament.

With two months left until Britain is due by law to leave the EU, investors and allies have urged the government to clinch a deal to allow an orderly exit from the club it joined in 1973.

“Tonight, a majority of honourable members have said they would support a deal with changes to the backstop,” May said, only two weeks after her divorce deal was crushed in the biggest parliamentary defeat in modern British history.

“It is now clear that there is a route that can secure a substantial and sustainable majority in the house for leaving the EU with a deal,” May said, adding she would seek “legally binding changes”.

The Irish backstop is an insurance policy that aims to prevent the reintroduction of a hard border between Ireland and the British province of Northern Ireland, a crucial part of a 1998 peace deal that ended decades of sectarian violence and preserve frictionless trade.

However, critics said it could bind the United Kingdom to the EU’s rules indefinitely.

Put forward by influential Conservative lawmaker Graham Brady and passed by 317 votes to 301, the proposal called for the backstop to be replaced with unspecified “alternative arrangements”, and said parliament would support May’s Brexit deal if such a change was made.