BRUSSELS (AFP) – EU ministers are set Monday to give Frenchman Michel Barnier the European mandate to negotiate Britain’s exit from the bloc, which he expects to start in earnest in mid-June following British elections.

Barnier will lock horns with Britain’s Brexit minister David Davis who has predicted “the talks will be tough and at times even confrontational,” despite a mutual desire for good future ties.

Ministers from the remaining 27 EU member states are set to meet in Brussels at 0900 GMT to give Barnier, a former European commissioner and French minister, his negotiating directives.

The directives are based on guidelines adopted after just a few minutes of debate at an April 29 summit in Brussels, which EU officials called a rare and remarkable show of unity.

“We expect also a quick process,” an EU diplomat told reporters when asked if the ministers would act as quickly on Monday as their leaders did last month.

The directives aim to shape the first phase of negotiations that are set to last two years, even if some EU officials suspect the timeline is too ambitious.

They deal with the rights of EU citizens in Britain and British citizens on the continent, as well as London’s exit bill and arrangements for the border in Northern Ireland.

EU leaders have agreed “sufficient progress” must be made on these three points before a new trade relationship can be struck.

That approach is opposed by Britain, which wants them to be discussed in parallel.

British Prime Minister Theresa May, who triggered the divorce process on March 29, said “the next five years will be among the most challenging in our lifetime” as Britain tries to untangle itself from four decades of EU membership.

– ‘Difficult’ Brexit bill –

May took over from David Cameron who resigned after a slim majority of British voters shocked the world last June when they chose to leave the bloc over complaints on immigration and other issues of sovereignty.

Cameron campaigned in vain for Britain to remain in Europe, stumbling in a referendum he himself had called to resolve divisions in his Conservative party.

Though she had officially backed Cameron’s pro-EU stance, May accepted the result and called snap elections on June 8 in a bid to bolster London’s negotiating position.

In her current election campaign, May repeated her threat to walk away from the negotiations with the EU if she deemed the terms on offer too onerous, although she said she wanted to secure a deal, including on new trade ties.

Barnier told EU colleagues on May 3 he does not expect negotiations to begin until mid-June when he hopes Britain’s post-election political climate will be more favourable to reaching an agreement.

Barnier conceded that settling Britain’s outstanding financial commitments to the EU would be “one of the most difficult” aspects of the negotiations.

He expressed concern that a failure to agree on the Brexit bill — possibly 60 billion euros ($67 billion) — could increase chances of a disorderly British withdrawal that would harm everyone.

Barnier has said there was no set sum but that it would be calculated using a “methodology” that he insists be worked out quickly.

The Brexit negotiator also outlined a provisional timetable leading up to the formal exit in two years.

He hopes for an agreement on the first phase between October and December 2017, then a launch of the second phase between December 2017 and spring 2018, then finalisation of a Brexit deal towards October 2018.

The aim would be to have the ratification process for the deal completed by March 2019, three months before the next European Parliament elections.