British Prime Minister Theresa May urged parliament on Tuesday to give her a mandate to renegotiate her Brexit deal with the European Union, setting up a major clash with Brussels just two months before withdrawal day.French President Emmanuel Macron quickly rejected May's bid to re-open talks that took 18 months conclude, saying it was the "best agreement possible and is not renegotiable".May herself had agreed the 585-page text with Macron and other EU leaders at a summit last month after tortuous negotiations that followed the 2016 Brexit referendum vote.But MPs rejected it by a historic margin on January 15, leaving Britain set to crash out of the EU after 46 years of membership in a blaze of economic and political chaos.With their country still bitterly divided over Brexit, MPs on Tuesday were preparing to hold a series of votes that could give them a much bigger say over what happens next.May is supporting one of the proposals, which would seek to remove a controversial "backstop" clause on Northern Ireland from the divorce agreement to be replaced by unspecified "alternative arrangements".The British leader promised that if this passed, she would seek a "significant and legally binding change to the withdrawal agreement" with the EU before Britain leaves the bloc as planned on March 29.Speaking after a phone call with European Commission President Jean-Claude Juncker, May acknowledged the opposition in Brussels to reopening the deal and said it "will not be easy"."We have the chance to show the European Union what it will take to get a deal through this House of Commons. What it will take to move beyond the confusion, division and uncertainty that now hangs over us," she said.Border backstop The rejection of May's plan significantly raised the risk that Britain leaves the EU with no new arrangements in place, leading to significant economic disruption on both sides of the Channel.MPs were set to vote from 19:00 GMT on the way forward, with amendments put forward including ruling out a "no deal" Brexit, delaying exit day and returning to the negotiating table.Brexit hardliners from May's Conservative party oppose the backstop, which could see Britain indefinitely tied to EU trade rules in order to keep open the border with the Republic of Ireland.The amendment backed by the prime minister calls for the backstop to be replaced with "alternative arrangements to avoid a hard border".Should she succeed, May has promised any revised deal would be put to a vote by MPs as soon as possible.If there is no deal by February 13, she has promised to give MPs a chance to vote on what happens next on February 14.'Groundhog Day' May accepted there was "limited appetite among our European partners" to changing the Brexit deal, which took almost two years to negotiate.Speaking on Monday, Sabine Weyand, deputy to EU Brexit negotiator Michel Barnier, said: "There's no negotiation between the EU and the UK. That negotiation is finished."It does feel like Groundhog Day."She said Britain risked crashing out of the EU without a deal "by accident" because London cannot decide what it wants.Irish Finance Minister Paschal Donohoe on Tuesday said Ireland's view was "unchanged"."The withdrawal treaty containing the backstop must be maintained," he said.'Block a disastrous no-deal' Tuesday's votes are the latest twist in the turmoil that the Brexit vote has unleashed in one of the world's top economies.Increasing numbers of government ministers have warned they will not accept the prospect of Britain leaving without a deal, immediately severing all ties with its largest trading partner.One of the amendments to be voted on Tuesday would allow MPs to bring in legislation that could force May to delay Brexit if she has no deal by February 26.It is backed by opposition Labour leader Jeremy Corbyn, who said: "The first duty we have is to block a disastrous no-deal."He warned that whatever the outcome of the prime minister's efforts, a delay to Brexit now seemed "inevitable".