London: Number 10 has told business leaders that Theresa May could storm out of Brexit talks over the “divorce bill”, The Sunday Telegraph can reveal. A senior Downing Street figure briefed industry and City bosses to prepare for the Prime Minister walking away from negotiations in September. The move would be designed for “domestic consumption” to show May was playing tough over the €100 billion (Dh419 billion) some EU figures want the UK to pay before leaving.

The briefing took place at a point after the general election was held last month and the figure has since left in the recent overhaul of Downing Street. Business leaders were told that while no final decision had been taken on walking out of talks, it was a distinct possibility. “I do think we are looking to be as hard-nosed, as hard-headed and as cold-eyed about this as it is possible to be,” said a source familiar with Number 10’s thinking. “If any of those actions take place it will be to work towards a single objective — getting the best deal that we can.”

The comments have been seen as an attempt to limit the backlash from markets if negotiations over how much Britain owes turn sour later this year. Government figures are still haunted by May’s speech at the Tory conference last October when the pound nosedived as she outlined her plan for Brexit.

However, the move would likely be seen as deliberately provocative by EU leaders, given both sides have called for a cordial approach to talks. It reflects the political difficulty May faces in explaining to the British public why the UK may have to pay tens of billions of pounds to leave the EU. Some polls have suggested that voters are vehemently against paying large sums to Brussels, yet UK officials are increasingly resigned to the fact that they will have to pay a fee.

The move echoes advice given by Sir Lynton Crosby, the Australian campaign guru, to David Cameron when he was renegotiating Britain’s EU membership before the referendum. The then prime minister was reportedly told to walk away from talks to get a better deal from Brussels. He declined and was later criticised for failing to win fundamental reforms.

A working group between the UK and EU is being set up in the coming weeks to negotiate the so-called “Brexit bill”. Estimates from Brussels range from €40 billion to €100 billion. A Number 10 source last night played down the idea of a walkout, saying: “This suggestion has no part in our plans.”