The European Union opened the door on Monday to Britain postponing its exit from the 28-nation bloc beyond the March 29 deadline, saying it would be a "rational solution" given the political crisis in the UK.European Council President Donald Tusk said he had discussed the "legal and procedural context of a potential extension" when he met on Sunday with British Prime Minister Theresa May, on the sidelines of an EU-Arab summit in Egypt's Sharm el-Sheikh."I believe in the situation we are in, an extension would be a rational solution but Prime Minister May still believes she's able to avoid this scenario," Tusk told a closing summit press conference.The European Union has been watching with growing alarm the possibility Britain will crash out of the bloc without a deal, risking chaos on both sides of the Channel.Britain remains as divided as ever over Brexit, which a narrow majority of voters called for in a June 2016 referendum.May sparked outrage at home when she suggested on Sunday that parliament may not be able to vote on her Brexit deal until March 12, just 17 days before Britain leaves the EU.The decision increases the chances that lawmakers will move next week to delay Brexit beyond March 29, to avoid a no-deal Brexit. May said on Sunday she was still discussing with the EU possible amendments to the deal's arrangements for the Irish border.Taking a united stand, the EU and its remaining 27 countries have repeatedly rebuffed May's efforts to reopen the Brexit deal struck with her government in November.Since lawmakers rejected her withdrawal deal last month, the prime minister has sought to address their concerns about the text's "backstop" arrangement.'Achieve that deal'London wants the "backstop" - the clause binding Northern Ireland into the EU customs union if a new deal to keep the border open is not found - to be time-limited or to be allowed to unilaterally end it.The EU opposes any changes to an arrangement designed to keep the border between British Northern Ireland and EU member Ireland flowing. It also sees the "backstop" as an insurance policy for the peace process in the British province of Northern Ireland.Brussels is not budging, though it is offering political reassurances.Tusk said "we'll face an alternative chaotic Brexit or an extension" under the current circumstances where it is "absolutely clear" to him there is no majority in the British parliament for May's deal.The former Polish premier added that "the less time there is until 29 of March, the greater the likelihood of an extension".This was not an EU plan but a reading of objective fact, he added.Tusk said he told May that "no matter which scenario, all 27 (EU countries) will show maximum understanding and good will".During a press conference on Monday in Sharm El-Sheikh, May said she believes she can still deliver Brexit on time."I've had a real sense from the meetings I've had here and the conversations I've had in recent days that we can achieve that deal," May said.The European Commission, the EU's executive arm leading the Brexit negotiations, is still working on the assumption that Britain will leave the bloc on March 29, commission spokesperson Mina Andreeva told reporters earlier in Brussels.She recalled that Britain would first have to request an extension and the remaining 27 EU countries would have to agree to it unanimously.May's negotiating team is due to return to Brussels on Tuesday for more talks.