British Prime Minister Theresa May will seek to unlock Brexit talks on Friday with a major speech in Florence, after Brussels demanded more clarity on the crunch issues of budget payments and EU citizens' rights.
May is expected to offer to meet Britain's obligations until the end of the current EU budget period, worth at least 20 billion euros, and will set out plans for a time-limited transition period.
A fourth round of negotiations with the European Commission is due to start next week, with London keen to make progress on the terms of the divorce so that talks can move on to trade.
"While the UK's departure from the EU is inevitably a difficult process, it is in all of our interests for our negotiations to succeed," the prime minister will say.
"I believe we can be optimistic about the future we can build for the United Kingdom and for the European Union."
The EU's chief negotiator Michel Barnier warned Thursday that "major uncertainty" remained on Britain's position on its three priorities -- citizens' rights, money and the Irish border.
May will urge the EU to be "imaginative and creative" -- but Barnier warned he was looking for "clear commitments".
Fifteen months after the referendum vote for Brexit, and six months after May triggered the two-year Brexit process, the shape of the withdrawal remains unclear.
Cabinet tensions over the issue exploded into public view last week when Foreign Secretary Boris Johnson, a leading voice for Brexit, laid out his own vision for life outside the EU.
He argued for a clean break with the bloc, a stance that dismays moderates who fear this will wreck Britain's relations with the world's biggest trade bloc.
Johnson will be in the audience when May makes her speech at the Santa Maria Novella church and museum, which some commentators dubbed an attempt at personal renaissance.
- Divorce bill -
Media reports suggest May will offer to meet Britain's share of the EU budget for two years after Brexit, to allay fears that some European countries will have to pick up the tab.
Downing Street said May would set out a plan for a "time-limited implementation period, offering certainty and clarity to businesses and citizens".
There is speculation the money could be paid for Britain's continued access to Europe's single market during this period, reported to be around two years.
However, ministers have said they will not accept free movement of labour after Brexit -- a key principle of the single market.
Britain's contributions for two years would be at least 20 billion euros (£18 billion, $24 billion) -- but this falls well below European estimates of Britain's Brexit bill.
The EU is also demanding Britain pay for long-term budget commitments, including contributions for infrastructure projects in poorer member states and pensions for EU officials.
Transport Secretary Chris Grayling told BBC radio that May's speech would not set out the "fine detail".
"What she is doing is setting out today the principles of a future relationship. She's talking about how we move the negotiations forward," he said.
- Citizens' rights -
Brussels is also looking for progress on the future of three million EU citizens currently living in Britain, with the two sides deadlocked on the role of the European Court of Justice.
Ending the court's jurisdiction is a totemic issue for eurosceptics in Britain, but Brussels insists Europeans must be able to appeal to its judges to protect their rights.
The Financial Times reported Friday that May will offer to enshrine any agreement on EU citizens rights in the final Brexit treaty, meaning it could not be amended by lawmakers.
As things stand, few believe there will be a breakthrough in time for an EU leaders meeting in October, when May's 27 counterparts will make their decision.
May will seek Friday to appeal to individual European leaders, over the heads of the European Commission, the executive arm of the bloc which is conducting the formal discussions.
While none are expected to attend Friday's speech, she will meet many of them at an event in Estonia next week, and is also meeting EU President Donald Tusk in London on Wednesday.
© 2017 AFP