"The best way we can spend this week is to rebuild trust", rather than tackle the big hard issues right at the start, a European source said.
German Chancellor Angela Merkel, who is considered one of the driving forces behind the European Union, said on Monday that she hoped negotiations would secure a "good agreement" for both parties but reiterated the unity of remaining member states.
There will be haggling over the terms, over money, but "the most important thing is to raise our eyes to the future. and think about the deep and special partnership that we want to build with our friends", he said.
"We want both sides to emerge strong and prosperous, capable of projecting our shared European values, leading in the world, and demonstrating our resolve to protect the security of our citizens. A deal like no other in history". Only when there is "sufficient progress" does the European Union want to look at creating a new relationship with Britain on things like trade and migration. Mr Case was principle private secretary to the Prime Minister before talking up this role. He and Davis are due to give a joint news conference in the evening.
Days after a suggestion from French President Emmanuel Macron that Britain could still choose to remain, Davis said there would be no backtracking from Prime Minister Theresa May's plan to deliver on Brexit, for which Britons voted in a referendum nearly a year ago. This has further opened the door for her opposition to push for a softer Brexit, in hopes of maintaining some of the agreements and pacts with the European Union, and on Sunday, June 18 of this year, five major business bodies of United Kingdom have released a joint open letter to the government calling for more openness in talks. In a tweet on Sunday afternoon, he said: "Back this weekend in my countryside, Savoie, to draw the strength and energy that the long hike requires".
"The UK has been crystal clear in our approach to the negotiations, the withdrawal process can not be concluded without the future relationship also being taken into account".
The third key issue is the future of the peace process in the British province of Northern Ireland, and the status of the border with the Republic of Ireland.
The first full face-to-face meetings between teams of European Union and United Kingdom negotiators began in the Berlaymont building at 11am.
German Foreign Minister Sigmar Gabriel told Sunday's Welt am Sonntag newspaper that "maybe there is now a chance to achieve a so-called "soft Brexit."' But he said staying in the single market would require Britain to accept European Union workers" freedom of movement.
Barnier wants agreement on the withdrawal, and on a transitional path to a future relationship, by October 2018, so that the European and British parliaments can ratify the deal by Brexit day in March 2019.
From his comments, it appeared that the Brexit talks will largely follow the EU's conditions and will centre on the two sides' new relationship only once sufficient progress has been made on the withdrawal issues.