Theresa May will speak with French President Emmanuel Macron and Irish Prime Minister Leo Varadkar as part of a flurry of conversations ahead of the critical European Council summit this week.
May is due to call her Paris-based counterpart this afternoon, having spoken to German chancellor Angela Merkel yesterday morning, as she attempts to win EU27 leaders around on Brexit.
Both France and Germany have so far shown little inclination to back the UK's calls for progress in talks, and the EC is widely expected to conclude sufficient progress has not been made, effectively blocking negotiators from being able to unlock the second stage of discussions to finally include trade and transition.
At the conclusion of the fifth round of talks last week, EU negotiator Michel Barnier said the two sides had reached a "disturbing" deadlock on the divorce bill.
As well as her flurry of phone calls, May is travelling to Brussels this afternoon for a dinner with Barnier and Jean-Claude Juncker. She will be joined by Brexit secretary David Davis and civil servant Olly Robbins.
Although it has been widely reported that the dinner was a last-minute addition to the schedule, and as such was not even in Juncker's diary, the Prime Minister's spokesman today insisted it had been planned for some time, saying it had been arranged around the time of May's Florence speech.
He also rejected suggestions the 6:30pm timing of the dinner implied it had been hastily added to the schedule, saying it was not "unusual in significant parts of the UK".
The spokesman said the dinner was "part of a wider programme of engagement that has taken place in recent weeks and will continue... going forward".
Dismissing questions over the previous dinner, which was leaked from the European side, to May's annoyance, the spokesman said the Prime Minister expected this evening's meeting to be "constructive".
"It is part of that process... part of moving forward," he said. "We are heading in the right direction."
The pound was up against both the dollar and the euro this morning, as traders hoped for a break in the impasse.
Paresh Davdra, chief executive of RationalFX, said: "Following last week’s comments from Barnier and Juncker that Brexit negotiations had reached a deadlock, analysts have viewed May’s meeting today as a positive step towards breaking it, which has buoyed the pound following a week of turbulence."
However, he noted it could be "another volatile week" for currency, with a number of key economic reports being released, not least the latest inflation figures.