Theresa May’s government will publish two white papers on customs and trade arrangements after Brexit, amid warnings from within government to expect two more thorny rounds of negotiations with the EU.

A senior government official told the Guardian that ministers remained deeply pessimistic about the hopes of adequate progress in this round of talks or those that will start in November.

They claimed it might take a bout of “theatrics” to force a breakthrough in December, perhaps involving a change of tone from the Brexit secretary, David Davis, that would allow the EU to say it had pushed Britain enough.

“He may have to emerge without a smile on his face,” said one source.

The UK government is desperate for the European commission to conclude that enough progress has been made on issues relating to the divorce settlement, such as financial liabilities, Northern Ireland and citizens’ rights.

Only then can officials move on to talks about the future relationship.



May will try to encourage the commission by declaring that “the ball is in their court”. She will use a statement to parliament on Monday to argue that a good deal is important for European countries as well as Britain: “So while, of course, progress will not always be smooth, by approaching these negotiations in a constructive way – in a spirit of friendship and cooperation and with our sights firmly set on the future – I believe we can prove the doomsayers wrong.”

May’s official spokesman said: “The prime minister has said that we want to see momentum, and that the response so far has been constructive.”

He said the white papers were part of the domestic parliamentary process, which involves a string of legislation to prepare the country for life after Brexit.

However, it is not clear how customs and trade arrangements can be pinned down when talks on those factors have yet to start.

Asked about the existence of secret legal advice believed to say that parliament could stop Brexit before 2019 if MPs think it is in the national interest, the spokesman said: “You will know we never comment on government legal advice but we’ve also always been entirely clear that we are leaving the European Union.”

At his daily press briefing in Brussels, the EC’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.

Concerns about the lack of progress in Europe has led to speculation that the government is ready to plough in money after Christmas to speed up preparations for the possibility of no deal.

A spokesman for the Department for Exiting the European Union said: “We go into the fifth round of talks confident we can build on the concrete progress we have made across a range of issues.



“We have taken decisive steps forward on citizens’ rights, Northern Ireland and on a large number of the separation issues.

“It’s important to continue that momentum and for the negotiations to move on to the next phase in order that we can discuss our future partnership.”