The fifth round of Brexit negotiations is coming to an end amid growing frustration at the apparent failure of the talks in Brussels to break the deadlock.
Brexit Secretary David Davis and the EU's chief negotiator Michel Barnier are expected to hold their customary end of talks press conference amid little sign of concrete progress.
On Tuesday European Council president Donald Tusk became the latest senior figure to warn the negotiations had not advanced sufficiently to move onto the second phase - including a new free trade deal.
While Theresa May has said she remains optimistic about the prospects for an agreement, she told MPs this week that contingency plans were being worked up in case the UK crashed out without a deal.
Mr Barnier is due to brief the leaders of the other 27 EU member states on the state of the negotiations when they meet next week for a summit in the Belgian capital.
So far, however, he has been adamant there has not been enough progress on the so-called "divorce" arrangements for him to be able to recommend they move on to phase two.
The EU side has been adamant that they need greater clarity on the issues of future citizens' rights and the border with Ireland as well as the thorny issue of the financial settlement.
In her Florence speech, Mrs May sought to reassure other EU leaders that the UK would fully honour its outstanding obligations while continuing to pay into the EU budget during a proposed two-year transition.
However there is frustration in Brussels that Mr Davis has so far been unwilling to put an actual figure on the "divorce bill".
Business leaders meanwhile have expressed growing impatience at the lack of progress, warning that they urgently need greater clarity as they come to make key investment decisions.
The director general of the British Chambers of Commerce, Adam Marshall, will use a keynote speech in Birmingham to say that it would be "unforgivable" if trade was damaged as a result of the "brinksmanship" of the two sides.
"Further delays to trade and transition talks would create a lose-lose scenario for everyone with a stake in the game," he will say. "It would be unforgivable for politicians on either side of the Channel to privilege brinksmanship and disruption over thriving trade."
Meanwhile Foreign Secretary Boris Johnson and Defence Secretary Sir Michael Fallon will reaffirm the UK's continued commitment to the collective defence of Europe after Brexit when they meet their Polish counterparts for talks in London.
Sir Michael will renew the UK's commitment to Nato's "enhanced forward presence" in Eastern Europe - including 150 British troops stationed in Poland in support of a US-led battlegroup - designed to deter Russian aggression.
Speaking ahead of the talks, Mr Johnson said: "This meeting is another demonstration of the UK's unbreakable commitment to European security, working with our allies such as Poland to ensure the stability and prosperity of our continent."
His comments echo a similar assurance given by Mrs May when she visited UK troops in Estonia, in an apparent softening of the Government's position after it previously appeared to threaten to end security co-operation if there was no deal on Brexit.