The EU says it won’t renegotiate the Brexit deal, but could its member states say otherwise?

Theresa May wants to head back to Brussels to renegotiate the Brexit deal.

Despite EU assurances that there is no more talking to be done, it remains unclear what sort of reception she can expect.

Theresa May agreed a Brexit deal with the EU in November. But when she took it back to Westminster, MPs rejected it by the biggest margin of defeat for a government in the history of parliament.

Subsequently, MPs narrowly backed a motion to call on the government to ditch the controversial “Irish backstop” part of the deal and replace it with “alternative arrangements” for avoiding a hard border in Ireland.

Many MPs, especially Brexiteers and the DUP, think the backstop, which keeps the UK inside the EU customs area, is a breach of sovereignty because it treats Northern Ireland differently from Great Britain in some respects. Others also worry it will become a permanent customs union, which they do not want.

The EU has publicly, and repeatedly, come out very strongly against renegotiation.

European Commission president Jean-Claude Juncker said this week: “The withdrawal agreement is the best and only deal possible. The European Union said so in November, we said so in December, we said so after the first meaningful vote in the Commons in January. The debate and vote in the House of Commons do not change that.”

In fact, less than 10 minutes after MPs voted to reject the backstop, a spokesperson for Donald Tusk, the president of the European Council, said: “The backstop is part of the withdrawal agreement, and the withdrawal agreement is not open for renegotiation.”

This seems unlikely at present.

The UK strategy throughout the whole of the talks has been to try to peel off member states and disrupt EU unity. Even before the referendum, former Brexit secretary David Davis said his first stop would be to negotiate individual deals with Berlin, or Paris.

But it hasn’t worked out like that and there’s no obvious reason to think things will change – unless pressure somehow gets to the EU at the last minute.

What’s more, the Commission’s positions are taken after talking to member states, and set by member states at European Council meetings. Donald Tusk, the first senior EU chief to intervene after the latest Westminster vote, is supposed to reflect the settled views of EU members when he makes public statements.

At the start of the year, the Polish foreign minister suggested adding a time limit to the backstop. He was quickly shot down by Leo Varadkar, the Irish prime minister, who said this was not the EU’s position, and nothing more was heard of it.

This is not the first time Poland has raised the issue – they’ve talked about it behind the scenes before – though it was the first time they’d gone public.

The truth is, the vast majority of countries are happy to follow Ireland’s lead on this question as a matter of principle. Ireland is adamant it will not accept a limited backstop.

There are a few rumours in Brussels that some states, such as Germany, are open to a pragmatic solution. But this doesn’t necessarily mean it has an answer that the UK could accept, and for now the balance of opinion among member states is to stand by Dublin.

It’s entirely possible the balance of opinion could shift – Theresa May is said to be trying to convince capitals directly. Still, she has no history of success in this regard.

Got an unanswered question about Brexit? Send it to editor@independent.co.uk and we’ll do our best to supply an answer in our Brexit Explained series