Theresa May has refused to put a figure on Britain’s Brexit divorce bill during the first phase of secession negotiations as EU leaders warn she will need to make a concrete offer in order to make progress.

Speaking at the European Council summit in Brussels the Prime Minister told reporters that the figure for the liabilities bill – estimated to be at least £20 billion – would only be named at the very final stages of talks.

EU leaders and negotiators however say those final stages will only be reached once the divorce bill is finalised – continuing the deadlock between the two sides.

Ms May had said in her Florence speech earlier this month that the UK would cover its costs in the current EU budget round and that no member state would lose out, but the PM has irked EU leaders by refusing to put a figure on this commitment.

“I’ve been very clear all along as the UK has, all along throughout this, that the full and final settlement will come as part of the final agreement that we’re getting in relation to the future partnership. I think that’s absolutely right,” she said at a press conference near the end of the European Council meeting on Friday.

The EU’s negotiators have repeatedly insisted on settling the issue of the divorce bill, as well as that of Northern Ireland and EU citizens’ rights, before any trade talks can begin.

UK officials had hoped that national leaders might be persuaded to change this mandate at European Council, but far from softening a line, national leaders have been even more explicit.

Theresa May: No Brexit breakthrough on the cards

Speaking at the summit, Dutch prime minister Mark Rutte said: “I suspect that if they want progress, the British Government will have to tell us at the very least — if they don’t give us a number — how they think they will be able to get to a number, together with Europe. Otherwise we’ll keep going round in circles.”

European Commission chief negotiator revealed at the end of the last round of talks that the divorce bill had not even been fully negotiated on during that week because of the complete breakdown in progress on the issue.

Brexit: the deciders Show all 8 1 /8 Brexit: the deciders Brexit: the deciders European Union's chief Brexit negotiator, Michel Barnier Getty Brexit: the deciders French President Emmanuel Macron Getty Brexit: the deciders German Chancellor Angela Merkel Reuters Brexit: the deciders Commission President Jean-Claude Juncker EPA Brexit: the deciders The European Parliament's chief Brexit negotiator Guy Verhofstadt Getty Brexit: the deciders Britain's Prime Minister Theresa May Getty Images Brexit: the deciders Britain's Chancellor of the Exchequer, Philip Hammond PA Brexit: the deciders After the first and second appointed Brexit secretaries resigned (David Davis and Dominic Raab respectively), Stephen Barclay is currently heading up the position PA

There was some good news for the UK at the summit, however, after European Council president Donald Tusk announced that the EU would begin internal preparations for trade talks so it could be ready to negotiate with Britain once the deadlock was broken.

“Brexit conclusions adopted. Leaders green-light internal EU27 preparations for 2nd phase,” he said.