Brussels: European Union leaders called for a united front at their first Brexit summit on Saturday as they prepared to adopt a tough strategy for two years of talks with Britain.
EU President Donald Tusk insisted Britain would also benefit if unity boosted the chances of a deal, after Prime Minister Theresa May accused the other 27 countries of ganging up on London.
The 27 leaders meeting in Brussels will approve guidelines saying trade talks can only start once London agrees divorce terms on citizens` rights, its exit bill and Northern Ireland.
"We need to remain united as the EU 27. It is only then that we will be able to conclude the negotiations, which means that our unity is also in the UK`s interest," Tusk said.
The meeting in Brussels is the 27 countries` first official Brexit summit since May triggered the Article 50 divorce process exactly one month ago.
The call for a united front comes hot on the heels of a war of words between May and German Chancellor Angela Merkel, who said Britain should not have "illusions" about the talks.
"There will inevitably be a price and a cost for Britain," French President Francois Hollande said, adding that "the aim of the summit is unity."
However, the unity call comes after years of bitter internal divisions within the bloc on everything from the euro and migration to how to tackle growing euroscepticism.On arrival at the summit, Merkel said the EU wants "good relations" with Britain but added that "we also want to defend, at 27, our common interests -- so far we have done extremely well."
The EU`s chief Brexit negotiator, Michel Barnier, said the bloc had a "clear line" on the talks. "But this unity is not directed against Britain, I think that it is also in its interest," he said.
The EU 27 have considerably toughened the guidelines since Tusk first unveiled them a month ago, with Brussels also drawing up a detailed list of citizens` rights.
Tusk said Europeans needed "solid guarantees for citizens and their families, who will be affected by Brexit on both sides -- this must be number-one priority for EU and the UK."
This referred to the fate of three million EU citizens living in Britain and one million Britons on the continent, with officials hoping for a resolution on their status after Brexit by the end of the year.
In a further move that will rile London, the EU is also set to back automatic membership for Northern Ireland if it reunifies with Ireland, and call for Spain to have a say over any deal that affects Gibraltar.
The leaders will also discuss for the first time the spoils of Brexit -- the relocation of EU medical and banking agencies that are currently based in London.
Virtually all of the 27 have put their hand up to win one of the agencies.
Any cracks in Europe`s unity are expected to emerge when the sides must agree on future ties with Britain, with export powers like the Netherlands urging a soft touch.
Dutch Prime Minister Mark Rutte said divorce talks "must not take too long. We need a good timing so that we can talk of our future relations."
The EU guidelines say that only when "sufficient progress" has been made on divorce issues can these trade talks begin, with sources saying they hope to do that by the end of the year.While the EU says citizens` rights is a priority, the most touchy issue of all is likely to be Britain`s exit bill.
This is estimated at around 60 billion euros ($65 million), which mainly covers financial commitments made by the bloc while Britain was a member.
The bill is politically toxic for Britain but also risks causing divisions among EU states as they debate how to plug any holes in the EU`s budget.
May`s decision to call a general election in Britain on June 8, in a bid to shore up her mandate and strengthen her negotiating position, has only stiffened their resolve.
The elections are "an internal problem she wants to resolve in the Conservative party, to have not a hard Brexit or a soft Brexit, but Theresa`s Brexit," said Luxembourg`s prime minister Xavier Bettel.
Actual Brexit talks are not expected to begin until after the British election, although the EU is set to give an official mandate to Barnier on May 22.