SLOW progress on the Brexit talks means it is unlikely that the EU will agree to move onto talks about its future trading relationship with the UK in October as Britain had hoped, Guy Verhofstadt has suggested.

Addressing MEPs, the European Parliament’s chief negotiator claimed it was the UK Government’s reluctance to produce “further clarity” on its positions on the financial settlement and on citizens’ rights, which was holding things up.

He said: "If it goes slowly, as is the case at the moment, it will be very difficult to say there is sufficient progress in October."

Ahead of more face-to-face talks with his opposite number, David Davis, the Brexit Secretary, Michel Barnier, the EU’s chief negotiator, repeated his appeal for clarity from the British delegation, tweeting that EU guidelines were “designed for serious and constructive negotiations but we need clear #UK positions on all issues”.

The latest interventions followed the rebuke by Jean-Claude Juncker, the European Commission President, that not a single one of the raft of policy papers Whitehall had produced for the talks had been satisfactory.

But Theresa May, speaking during her trade mission to Japan, hit back, insisting that it was the UK, which was making the running in the Brexit negotiations

The Prime Minister also insisted she remained prepared to walk away from the talks without a deal if what was on offer from Brussels proved unacceptable but an EU diplomat warned that such rhetoric was not helping the atmosphere of the negotiations.

"We have been publishing a series of papers over the summer, there will be more papers to come, where we are setting out the key issues that both sides need to address, the options that we have, the ideas we have, of how to deal with those.

"It's the United Kingdom that has been coming forward with the ideas and with the clarity about the future," declared Mrs May.

Asked if she still believed no deal was better than a bad deal, she told the BBC: "Yes, that is right. But if you talk about the point at which we leave the European Union, we want to ensure that at that point we do have a deal and that we have a deal that is the right deal for the UK."

She dismissed Labour's new support for remaining in the single market and customs union during a transitional period after Brexit as "yet another position from them".

The PM added: "What I set out in my Lancaster House speech is you can't be a member of the single market without being a member of the European Union and we are leaving the European Union."

But Claus Grube, Denmark's ambassador to the UK, urged Mrs May to drop her "no deal" rhetoric, saying it was not helping the atmosphere of the talks.

“It is now more than a year ago that the referendum took place. It's been a long, let's say, a very British debate, with a lot of wishful thinking about the future and how to get out of the EU; a lot of 'cake and eat it,'" he added.

Meanwhile, Lord Hague, the former Foreign Secretary, claimed the Conservatives' failure to win the General Election outright would mean a "worse" Brexit deal.

He told BBC Radio 5 live that Mrs May's loss of her Commons majority had weakened her negotiating hand and, consequently, the UK would pay a "bigger price" for leaving.

"I don't think calling the election was a mistake. The result was a mistake; collectively, by the people of this country.”

The Tory peer went on: "The EU know that the result of the British election weakened the British Government's negotiating position. It absolutely did.

"So Britain will get a worse deal as a result of the election; there is no question about that," he added.