The request will be considered at an emergency European Union summit on April 10, where it requires the unanimous agreement of the leaders of the remaining 27 member states. The officials spoke on condition of anonymity because they weren't authorized to disclose information before it was made public. If an extension lasts beyond May 22, the United Kingdom would be obliged to participate in elections to the European Parliament. Officials worry that the legitimacy of European institutions could be jeopardized if the population of a member state is not involved in the process.
Jo Stevens MP, leading supporter of the People's Vote campaign, said: "It was right for the Government and Labour to consider alternatives to the prime minister's broken Brexit deal, but it is no surprise that an attempt to force an agreement inside a few days seems to have failed".
There are also concerns in Europe that some British politicians who want to provoke a "no-deal" Brexit might try to make trouble from inside the bloc, a course that outspoken Brexit advocate Jacob Rees-Mogg suggested Friday.
Theresa May must go to the European Council and ask for a longer extension to avoid the current cliff edge.
"We could veto any increase in the budget, obstruct the putative European Union army and block Macron's integrationist schemes".
One EU diplomat said that there was rising concern among member states that they would not get "sincere co-operation" from Britain, which could hurt how the bloc functions. "I would call it a "flextension", the official said. So the PM could be forced to accept either a Brexit delay of a year or so, or indeed (still not impossible) a no-deal Brexit on 12 April.
Britain's upper House of Lords is set to resume debate on the measure Monday.
Mr Farage also accused the Prime Minister and parliamentarians of trying to "kill Brexit stone dead".
The plan would have to be agreed unanimously by all 27 countries.
If May accepted, Britain would have to hold elections to the European parliament in May, the official said.
May offered to quit last week to get her deal passed but it was defeated for a third time last Friday, the day Britain was originally due to leave the EU.
In her letter, May said she wanted to make sure that Britain left the bloc after 46 years in an orderly manner, with an agreement that could help unwind intricate political, security, diplomatic and economic ties.
Political analysts in London said May probably knew that her new deadline will be rejected because European Union leaders do not think she can get her deal through parliament any time soon.
Speaking during a visit to south Wales to mark his party's victory in the Newport West by-election, Jeremy Corbyn said: "There's been no obvious move on the side of the government as of yet, we're continuing those talks".
"This crisis requires compromise and time to reach a sensible resolution".
"We do need change if we're going to compromise", said Keir Starmer, the party's Brexit spokesman, Keir Starmer, said, adding that Labour wants the talks to continue.
Last Friday, May did the unthinkable by asking Labour to negotiate with her on a deal that might work for both - although some in Labour said she was luring the party into sharing responsibility for her failure.