EU rules out Brexit changes, but could help May

May on Monday postponed Tuesday's crunch vote in the British parliament on the deal, after facing enormous opposition to the agreement seal by EU and UK negotiators only two weeks before.

Juncker, however, in a speech to the European Parliament poured cold water on May's efforts to seek a legally-binding guarantee that the backstop arrangement, which would keep the UK closely-aligned with the EU's customs rules if there is no trade deal at the end of the transition period, could be unilaterally revoked by the UK.

"The deal we achieved is the best possible. It's the only deal possible. There is no room whatsoever for renegotiation," Juncker told MEPs in Strasbourg, adding that there is "enough room" to give further clarifications and interpretations on the backstop.

'Cannot fathom it'

German state minister for Europe, Michael Roth arriving to a meeting in Brussels also warned not to expect too much from May's meeting in Berlin.

"There are ongoing talks, but I am at a loss of fantasy as to where we possibly could change anything in the deal. What we have arduously negotiated from both sides, cannot be just opened up again now. The only positive I am seeing is that the EU-27 are very united on this," he said.

"I can't fathom that those who have put PM May in this situation might want to stand responsible for the UK to slide into a hard Brexit," Roth added, saying "there will be in principle no new pledges to open up the agreement again."

After meeting May, Merkel reportedly ruled out further negotiations to her parliamentary group in Berlin, but said efforts were being made to give Britain reassurances.

France' Europe minister also said in Brussels there was little room for manoeuvre.

"We are very much concerned about the postponement of the vote on the withdrawal agreement. We've done a lot to help the UK. This withdrawal agreement is the only possible agreement and we've done a lot of concessions to reach it," Nathalie Loiseau said.

France has been one of the key opponents of keeping the UK in the EU's customs union without a trade deal, fearing Britain might use its access to undercut taxes and common rules.

Emergency fixes?

May will have a chance to plead with EU leaders on Thursday, when they gather for a summit in Brussels, to give her legally-binding assurances that the backstop will not be used, or will be temporary.

Rutte in 2016 secured a similar additional document to the EU-Ukraine association agreement after Dutch voters in a non-binding referendum rejected the deal.

With the EU's legal interpretation in hand, Rutte managed to secure parliamentary majority to ratify the agreement.

Another option could for EU leaders to deal with the matter in a conclusion at the end of the summit, which is not a legally-binding document but sets the political direction for the EU.

Recently Spain has managed to extract clarification on the status of Gibraltar at the Brexit summit in November attached to the withdrawal agreement.

No deal?

May's spokesman meanwhile said that the British government intends to hold the postponed vote on the Brexit deal in parliament by 21 January.

With Brexit day, 29 March 2019, only four months away, the EU is now gearing up for the possibility that the EU will sever ties with the EU without an agreement on how it should be done.

Loiseau said the French parliament voted on Monday to authorise the government to adopt ordinances to prepare for a no-deal Brexit.