BRUSSELS (AP) -- European Union leaders on Sunday sealed a divorce deal with Britain, and issued a warning to U.K. politicians who within weeks will approve or reject it — this offer is as good as it gets.
Amid criticism of the deal from lawmakers on all sides of Britain's EU debate, European Commission chief Jean-Claude Juncker said the U.K. couldn't hope to negotiate better terms before its departure in March.
"I am totally convinced this is the only deal possible," he said. "Those who think that by rejecting the deal that they would have a better deal will be disappointed the first seconds after the rejection."
For once, U.K. Prime Minister Theresa May was in complete agreement.
"This is the deal that is on the table," she said. "It is the best possible deal. It is the only deal."
Now that the EU has approved it, May must sell the deal to British parliamentarians — a huge task considering the intense opposition from pro-Brexit and pro-EU lawmakers alike.
May said Parliament would get a vote before Christmas, and argued lawmakers had a duty "to deliver Brexit" as voters decided in a 2016 referendum.
"The British people don't want to spend any more time arguing about Brexit," she said. "They want a good deal done that fulfils the vote and allows us to come together again as a country."
The last big obstacle to a deal was overcome on Saturday, when Spain lifted its objections over the disputed British territory of Gibraltar. It took EU leaders a matter of minutes at Sunday's summit in Brussels to endorse a withdrawal agreement that settles Britain's divorce bill, protects the rights of U.K. and EU citizens hit by Brexit and keeps the Irish border open. They also backed a 26-page document laying out their aims for future relations after Britain leaves on March 29.
At a bittersweet meeting, EU leaders expressed sadness at the departure of Britain, the first country ever to leave the bloc.
"A country leaving the EU doesn't give rise to the raising of Champagne glasses or applause," Juncker said. "It is a sad day and everybody who spoke today during the European Council attempted to express their sadness."
German Chancellor Angela Merkel said her feelings were "ambivalent, with sadness but on the other hand also some kind of relief that we made it to this point."
"I think we managed to make a diplomatic piece of art," she said.
May said she wasn't sad, because Britain and the EU would remain "friends and neighbors."
"I recognize some European leaders are sad at this moment, but also some people back at home in the U.K. will be sad at this moment," she told reporters.
But May said she was "full of optimism" about Britain's future.
Dutch Prime Minister Mark Rutte said the deal — the product of a year and a half of often grueling negotiations between Britain and the EU — was regrettable, but acceptable.
"I believe that nobody is winning. We are all losing because of the U.K. leaving," Rutte said. "But given that context, this is a balanced outcome with no political winners."
The deal must still be ratified by the European Parliament, something that its president, Antonio Tajani, said would likely take place early in 2019.
Tajani said a "large majority" of European parliamentarians supported the deal.
The same can't be said of British lawmakers.
May is under intense pressure from pro-Brexit and pro-EU British legislators, with large numbers on both sides of the debate opposing the divorce deal and threatening to vote it down. Brexiteers think it will leave the U.K. tied too closely to EU rules, while pro-Europeans say it will erect new barriers between Britain and the bloc — its neighbor and biggest trading partner.
Pro-Brexit Conservative lawmaker Iain Duncan Smith said Sunday that May should demand new conditions from the EU. He said the deal as it stands "has ceded too much control" to Brussels.
May insists her deal delivers on the things that matter most to pro-Brexit voters — control of budgets, immigration policy and laws — while retaining close ties to the U.K.'s European neighbors.
In a "letter to the nation" released Sunday, May said she would be "campaigning with my heart and soul to win that vote and to deliver this Brexit deal, for the good of our United Kingdom and all of our people."
Irish Prime Minister Leo Varadkar said he thought May's chances of getting the agreement through Parliament were strong.
He said British lawmakers would see that "the alternative is a no deal, cliff edge Brexit which is something of course that we all want to avoid."
"Any other deal really only exists in people's imaginations," he added.