Britain on Wednesday pressed the European Union to secure a post-Brexit trade deal by mid-October, despite deadlock in talks and calls for movement on key areas of disagreement.

Prime Minister Boris Johnson and EU Council president Charles Michel spoke by phone, in a call a source in Brussels said the British leader had requested.

Michel said he had urged Johnson to clarify the UK position on the deadlocked negotiations, restating the EU's commitment to a deal "but not at any cost".

"Time for the UK to put its cards on the table," he tweeted.

Johnson's office said soon afterwards he had also reaffirmed London's desire for an agreement and that it was prepared to walk away if none was reached by October 15.

That would mean Britain having an "Australia-style" relationship with the 27-member bloc from January 1 next year, it said in a statement.

Australia does not have a trade agreement with the EU and deals with the bloc on World Trade Organization terms, with tariffs and quotas the UK government had wanted to avoid.

- State of play -

The call came just over a week before Michel hosts an EU leaders' summit on October 15, which Johnson says is the final date to show progress in the talks before he could pull the plug.

But Brussels has refused the recognise the deadline.

EU officials say no deal is possible unless Johnson explains how he plans to meet the bloc's demands on fishing quotas, state subsidies and fair competition rules.

Diplomats say Johnson must take a more direct role in the process, which is increasingly seen as brinkmanship on both sides of the Channel.

But an EU source described the conversation with Michel as simply a "state-of-play call".

"We keep insisting on a deal which would be good for both sides and urge the UK to move," the source said.

Another source said the call had lasted 20 minutes and was not a negotiation between the two leaders. 

Johnson had insisted on the importance of his October 15 date and of coming to a deal on fish, the source said.

Michel countered that for Europe the "level playing field" rules for fair competition were just as important.

He also warned that Britain has not moved far enough on how they would be overseen.  

Next week's EU summit -- to which Johnson, as the leader of a former EU member, is not invited -- is the last one scheduled until December.

But an extraordinary meeting would be possible if there is a deal to sign, the source said.

- 'Landing zone' -  

France's minister for European Affairs, Clement Beaune, said member states would prefer Britain to leave the single market without a trade deal rather than compromise on their priorities.

"We are clear: We will not accept a bad deal," he tweeted.

"Our priorities are firm and defined: fishing, fair competition and clear rules to ensure the deal is respected."

UK and EU negotiators met again in London, as Johnson's senior Cabinet colleague Michael Gove said talks would fail if Brussels maintained an "intransigent approach".

But he signalled one advance allowing British food exports to be recognised under the bloc's "third-country" regime.

Apparent EU reluctance to list the UK on the third-country list had sparked British claims of a potential "blockade" on food exports between the mainland and Northern Ireland.

Northern Ireland, which will have Britain's only land border with the EU from next year, will remain subject to some of the bloc's rules.

Gove told a parliamentary committee there were grounds for "steady optimism" and the talks were "proceeding in a constructive way".

UK chief negotiator David Frost also said there was "quite good progress", adding: "The landing zone in the nature of the agreement is clear, if not exactly pinned down yet".