Theresa May will urge other EU leaders to give ground on the issue of the Irish border when she addresses them at a summit in Brussels later.

Brexit talks are deadlocked over the border, but the EU says it's up to the UK to bring new ideas to the table.

BBC political correspondent Iain Watson says Mrs May will try to strike an upbeat tone about the significant progress that's been made.

But he says expThe prime minister will address her fellow leaders on Wednesday evening, but won't be present at the meal where they will decide what to do next.

It had been hoped that they would agree to call a special Brexit summit next month to sign off the terms of a deal between the UK and the EU, but with such a deep chasm between the sides over the Irish border, the leaders are likely to be reluctant to do that.

The border between Northern Ireland and the Republic of Ireland will become the border between the UK and the EU when Britain leaves on 29 March next year.

Both sides want to avoid that border becoming "hard" - i.e. having checkpoints or other physical infrastructure to carry out checks on goods - but they can't agree on how that should be done.

A key sticking point is the so-called backstop - the safety net should no Brexit deal be reached - how long it should last and what form it should take.

Ahead of the Brussels gathering, the president of the European Council said there were "no grounds for optimism" that the two sides could bridge their differences but appealed for "goodwill and determination" to try and bring an agreement nearer.

Mrs May isn't, though, expected to table any new proposals to end the border impasse.

Downing Street said she has told fellow ministers not to be "downhearted" if fellow European leaders do not set a date for a November summit, amid growing expectation in government that any final agreement may be pushed back to December.ectations of any sort of breakthrough at the meeting are low

.On the eve of Wednesday's summit, former Conservative prime minister Sir John Major attacked Brexiteers, saying "those who promised what will never be delivered will have much to answer for."

"They persuaded a deceived population to vote to be weaker and poorer. That will never be forgotten - nor forgiven."

Sir John is among a host of former senior politicians, including Tony Blair, and ex-deputy prime ministers Lord Heseltine and Nick Clegg, stepping up calls for another referendum.

They have written a series of articles in European newspapers backing a so-called People's Vote, with the option to remain in the EU.

Sir John's remarks were met with barbed responses from Jacob Rees-Mogg and other Conservative Brexiteers who said he had compromised the UK's sovereignty by signing up to the Maastricht treaty in the early 1990s without consulting the people.

Elsewhere, while some of Mrs May's MPs have urged her not to pay any money to the EU unless a deal is struck, Chancellor Philip Hammond - who backed Remain - is understood to have told the cabinet the UK could face a big bill at the end of any transition period even if none reached.

According to the Daily Telegraph, that bill could be £36bn.