Boris johnson and ursula von der leyen agreed on saturday to work together to unlock an eu-uk trade deal, as negotiations moved into a new intensified phase and the mood around the talks improved.
Britains prime minister and the european commission president are now personally engaged in trying to unblock talks, notably on state aid, dispute resolution mechanisms and fisheries.
It was the first time mr johnson and ms von der leyen have spoken since june, but the conversation left both sides convinced a deal was possible. eu leaders will take stock of progress at a summit on october 15-16.
After a video meeting on saturday, both sides agreed on the importance of finding an agreement, if at all possible, as a strong basis for a strategic eu-uk relationship in future.
The commission president tweeted that it had been a good phone call; it was not a negotiation, rather a chance for both sides to take stock of progress and to stress their priorities.
Mr johnson put a particular focus on fish in the call while the eu side stressed the need for strong level-playing field guarantees on the uks subsidy regime.
Both stressed they were continuing to prepare for the possibility of no deal being struck.mr johnsons allies said the prime minister was very focused on the eu summit in mid-october as a moment for clarity on whether a deal is possible or not.
Michel barnier, eu chief negotiator, has previously suggested a more realistic deadline for agreeing a deal is the end of the month, giving the european parliament sufficient time to ratify any agreement.
Talks between the negotiating teams led by mr barnier and david frost on the uk side will resume in london next week. if eu leaders decide at their brussels summit that a deal is possible, a final dash to the line will begin.
The personal involvement of mr johnson and ms von der leyen is seen as the start of the end game of talks, as the lead actors get involved to attempt to engineer a political breakthrough.
In a joint statement, they agreed that progress had been made in recent weeks but that significant gaps remained, notably but not only in the areas of fisheries, the level playing field and governance.
Brussels is determined to ensure a robust mechanism for dealing with britain if it breaks its commitments under any trade deal. the issue has assumed new urgency since mr johnson introduced legislation that breaks the uks withdrawal treaty with the eu.
Lord frost and mr barnier were instructed to work intensively to try to bridge those gaps. but mr johnson and ms von der leyen also agreed to speak on a regular basis.
The vast majority of the prospective free trade agreement which aims to deliver tariff and quota-free trade between the two sides is now in place, including provisional agreements on goods, services, transport, energy, social security and other issues.
In many areas of our talks, although differences remain, the outlines of an agreement are visible, lord frost said on friday.
British officials privately believe that the deal will not founder on issues of state aid and how to resolve disputes or fisheries, when so much is at stake politically and economically on both sides.
The question is whether mr johnson and eu leaders, represented by ms von der leyen, can resolve differences that strike at the heart of the sovereignty arguments that fuelled brexit.
The british prime minister is under pressure to offer more access to eu fishing fleets and reassure the eu that there are mechanisms in place to stop the uk engaging in a subsidy race.
The eu will also be expected to move on both issues although mr barnier has already significantly softened demands from brussels over britains state aid policy.
One british official acknowledged as much: whatever happens now, we will be able to claim victory on state aid because they have already moved.
That provides mr johnson with some cover when he considers making further concessions on the state aid regime and fishing rights. france is pushing particularly hard for a good deal for its fleet.
Those involved in the 2016 brexit campaign say the prime minister and fellow brexiter ministers such as michael gove and rishi sunak are determined to get a gove, who is in charge of no-deal planning, is said by fellow eurosceptics to fear the possibility of a fractious parting of ways and chaos at the border.