'The ball is in your court now' - says both Theresa May to Brussels, and Brussels to Theresa May
Brussels has issued a fresh warning that it is up to the UK to come forward with proposals if it wants to break the deadlock in the stalled Brexit negotiations.
As a fifth round of talks was opening in the Belgian capital, Theresa May called for "flexibility" on both sides so they can move forward to the second phase - including a free trade deal.
In a statement to MPs updating them on progress since her Florence speech last month, the Prime Minister will say that the initiative now lies with the EU side, adding "the ball is in their court".
But at his daily press briefing in Brussels, the European Commission's chief spokesman, Margaritis Schinas, insisted the next move had to come from the UK.
"There is a clear sequencing to these talks. There has been so far no solution found on step one, which is the divorce proceedings, so the ball is entirely in the UK court for the rest to happen," he said.
His comments follow the latest assessment of the EU's chief negotiator, Michel Barnier, that there still has not been "sufficient progress" on the issues of citizens' rights, the border with Ireland and the UK's "divorce bill" for the talks to move forward.
Downing Street insisted there had been a "constructive" response to Mrs May's Florence speech in which she promised to honour the UK's outstanding financial commitments and offered to continue paying in to the EU budget during a two-year transition following Brexit.
The PM's official spokesman said: "The Prime Minister said after her speech in Florence that the intention was to create momentum. I think we have seen that momentum.
"The response from the EU and its leaders has been constructive."
However it looks increasingly unlikely that EU leaders will agree that they can move forward to the second phase when they meet in Brussels later this month.
European Commission president Jean-Claude Juncker has warned that it would take "miracles" for them to be able to move on by the time of the summit on October 19-20.
In her Commons statement, Mrs May will tell MPs she is "optimistic" that she will get a positive response from the remaining 27 member states and they will prove the "doomsayers" wrong.
"A new, deep and special partnership between a sovereign United Kingdom and a strong and successful European Union is our ambition and our offer to our European friends," she will say.
"Achieving that partnership will require leadership and flexibility, not just from us but from our friends, the 27 nations of the EU.
"And as we look forward to the next stage, the ball is in their court. But I am optimistic we will receive a positive response.
"Because what we are seeking is not just the best possible deal for us - but also the best possible deal for our European friends too."
She will acknowledge that "progress will not always be smooth" but will seek to strike a positive note about the Brexit process.
"By approaching these negotiations in a constructive way - in a spirit of friendship and co-operation and with our sights firmly set on the future - I believe we can prove the doomsayers wrong," she will say.
"I believe we can seize the opportunities of this defining moment in the history of our nation."
The Government is publishing white papers setting out policy on trade and customs following Brexit.
Liberal Democrat leader Sir Vince Cable said: "Theresa May says the ball is in the court of the European Commission. But she will find the ball comes back fast, with top spin.
"The Prime Minister has been wrong-footed by members of her own Cabinet, most notably her ambitious Foreign Secretary. As we start the fifth round of negotiations, it is advantage EU27 because they can see how divided this Government really is.
"The Government is now too weak to deliver a Brexit that will satisfy anyone, least of all the British people. And Brexit should not be a spectator sport - the people should have the final say on any deal."
A Conservative member of the Commons Foreign Affairs Committee warned that Britain leaving the EU without a deal would be bad for both the UK and Europe.
Nadhim Zahawi told BBC Two's Daily Politics: "It would be very, very difficult for the UK economy but it would be equally difficult for the EU27.
"Remember, we inject about £60-70 billion a year of demand into the EU27, so it's in nobody's interest. There are no advantages of a no deal. It's a bad deal to have no deal on both sides."
Meanwhile, there were complaints at Brexit Secretary David Davis's decision to attend a meeting of the Government's business council in Downing Street rather than travel to Brussels for the negotiations.
Labour MP Peter Kyle, a leading supporter of the Open Britain campaign against a hard Brexit, said: "Theresa May says the ball is in the EU's court, yet David Davis can't even be bothered to pick up his racket.
"Britain deserves much better than a part-time negotiator. The clock is ticking, the time left to negotiate is finite, and every day of fruitless talks takes us closer to a destructive Brexit with no deal at all.
"David Davis needs to pull his socks up, get on the Eurostar, and negotiate for Britain rather than posture in London."