Theresa May will appeal to Leavers and Remainers to put a stop to their bitter feuding as she lays out her strategy for negotiating Britain's departure from the European Union.

The Prime Minister is expected to give the most detailed insight yet into her approach to the forthcoming talks with Brussels in a major set-piece speech on Tuesday.

Downing Street refused to be drawn on reports that she will set out plans for a "hard Brexit" - pulling of the single market and the European customs union in order to regain control of immigration and end the jurisdiction of the European Court of Justice.

Although the exact contents of the speech are said to be a closely-guarded secret, The Sunday Telegraph quoted a government source as saying: "She's gone for the full works. People will know when she said 'Brexit means Brexit', she really meant it."

Writing in The Sunday Times, Brexit Secretary David Davis said the Government would be seeking to forge a "strong new partnership" with the remaining 27 member states.

"We don't want the EU to fail, we want it to prosper politically and economically, and we need to persuade our allies that a strong new partnership with the UK will help the EU to do that," he wrote.

He also indicated that the Government would consider some form of transitional arrangement - a move likely to be regarded with suspicion by hardline Brexiteers who have been demanding a clean break.

"It proves necessary we will consider time for implementation of the new arrangements," he said.

Pro-Remain former education secretary Nicky Morgan, who was sacked by Mrs May, said the Prime Minister should put "maximum participation" in the single market at the "heart" of her negotiating strategy and warned her not to damage the economy.

"The Government will be doing a disservice to the country and to both Leave and Remain voters if it dogmatically pursues a hard, destructive Brexit where immigration control is the be all and end all, our economy is undermined, and people are left poorer," she said.

Most attention, however, will inevitably be centred on her approach to key issues around the single market, the customs union and free movement of labour.

Mrs May will deliver her address amid the 19th century splendour of London's Lancaster House - scene of numerous international summits - a venue chosen to emphasise Britain's continuing global leadership.