By Gabriela Baczynska and John Chalmers
BRUSSELS, Oct 19 (Reuters) - European Union chiefs are so fed up of Brexit that when they clinched a deal with Prime Minister Boris Johnson this week they did not want to entertain the need to delay Britain's departure beyond Oct. 31.
But if Johnson does seek an extension for the divorce - as now seems likely after his failure to get the agreement approved in parliament on Saturday - there is very little chance that the other 27 members states would refuse.
"I can't see them refusing," Anand Menon, director of UK in a Changing Europe and a Brexit expert, told Reuters. "They don't want no deal and they certainly don't want to be blamed for it."
If the 27 are asked to agree on a new deadline, it is likely that they would do so at a hastily convened emergency summit before the end of October, possibly next weekend. Their ambassadors are due to meet in Brussels on Sunday morning.
The British parliament voted in favour on Saturday of an amendment that withheld support for the Brexit deal and as a result Johnson is obliged, by law, to request a postponement.
Johnson has insisted that he will not seek a delay beyond Oct. 31 and he reiterated that in parliament after the vote, though he has not explained how he will get around it.
The EU 27 have already agreed twice to postpone Brexit from the original deadline of March 29 this year.
FRUSTRATION IN BRUSSELS
However, frustration has mounted among them over the distraction of a process that has dragged on for three-and-a-half years since Britons voted in a referendum to leave the EU.
After the second extension they said it would be the last one, and French President Emmanuel Macron has been the most outspoken and hawkish among the 27's leaders on the issue.
His camp stresses the cost of protracted uncertainty in terms of sapping the EU's political capital and attention to face challenges from climate and migration to international crises, as well as economic cost for companies that have invested in contingency preparations for a no-deal Brexit.
Britain's House of Commons last month passed a law demanding that the government seeks a postponement until the end of January 2020 to avoid an abrupt split on Oct. 31 if a divorce deal is not approved by parliament by Oct. 19.
Despite French misgivings, the EU has made repeatedly clear it would not want to be seen pushing a member state out and that its absolute priority is to avoid a no-deal Brexit, especially one for which it would take the blame if it refused an extension.
However, an extension can only be granted by unanimity among the 27 and, asked whether there was any serious risk that Macron could refuse it, an EU official said: "No."
"If there is a chance of a deal, they will never choose no deal," said Nick Petre, spokesman for the Renew Europe group of liberals in the European Parliament that includes Macron.
A ONE-MONTH DELAY?
It is, however, possible that the EU 27 will grant a "technical extension" of one month - instead of the Jan. 31 deadline Johnson is obliged to request - to give Britain and the European Parliament time to approve the deal clinched this week.
"It can still just be a technical extension, only until the end of November. And they could still get out of it if they manage to pass it before October 31," said an EU diplomat who deals with Brexit.
Another EU diplomat said the length of an extension and conditions attached would depend on the purpose behind the request.
"If we still hope to be able to salvage this deal, we'd be looking at shorter ones," the diplomat said. "Then, if we are looking at elections or second referendums, a longer one would most likely be needed. At this stage, it really depends on what happens in Britain in the coming hours."
Many in Brussels believe there could be no more extensions beyond mid-2020 as the bloc needs the rest of the year to prepare its new, long-term budget from 2021 and needs to know whether Britain will go on paying.
(Reporting by John Chalmers and Gabriela Baczynska Editing by Ros Russell)