Mr Johnson personally interupted a meeting between UK negotiator David Frost and his EU counterpart Mr Barnier earlier this week.
The PM met with Mr Barnier before a crunch dinner on Tuesday, reminding the EU talks chief he expected a deal this summer.
A UK Government spokesman said: “The dinner on Tuesday provided a constructive opportunity for the Chief Negotiators to meet in a more informal way ahead of the specialised sessions. Deputy Chief negotiators were also in attendance.
“The PM briefly dropped in ahead of the dinner and reiterated his desire for the intensified process to reach an outline agreement this summer.”
The specialised session on Wednesday covered goods, services, fisheries, governance, LPF and law enforcement, the spokesman said.
This is a developing story, more to follow…