Politicians line up to replace Prime Minister Cameron

At the same time, EU officials tell Britain not to expect favorable trade deals post-Brexit.

The line officially began forming for Conservative Party members angling to replace Prime Minister David Cameron on Wednesday while European Union officials doubled down on warnings that Britain can’t expect favorable trade deals post-Brexit without giving ground on issues such as immigration.

Work and Pensions Secretary Stephen Crabb was first to formally declare for the post. Early frontrunners expected to soon join the fray include former London mayor and European Union “leave” leader Boris Johnson along with de facto “stop Boris” leader Home Secretary Theresa May. A new leader likely will be in place by early September.

Cameron announced he would go after Thursday’s referendum that saw the United Kingdom vote to drop out of the EU.

Cameron says he wants the new leader to negotiate details of the split with the EU. Still, he has lobbied for close EU ties and access to the EU common market. But one reason Brexit won the day was frustration over immigration. EU leaders meeting Wednesday in Brussels minus Cameron stressed that Britain can’t cherry-pick advantageous trade conditions.

“Leaders made it crystal clear today that access to the single market requires acceptance of ... freedom of movement,” European Council President Donald Tusk said. “There will be no single-market a la carte.”

The council, which includes the EU heads of state, issued a statement saying the EU hopes to have the U.K. as a “close partner.”

Scotland’s leader, Nicola Sturgeon, met Wednesday with EU leaders including Jean-Claude Juncker, the president of the European Commission in Brussels, to seek a way for Scotland to stay in the bloc. A majority of Scots voted “remain.”

In Britain, Brexit fallout did not solely strike the Conservative Party. Labour Party leader Jeremy Corbyn, accused of failing to strongly support the “remain” faction, refused to resign.

Ed Miliband, Corbyn’s predecessor as the Labor Party’s leader, added Wednesday to calls for Corbyn to resign.

David Cameron says he wants the new leader to negotiate details of the split with the EU. Still, he has lobbied for close EU ties.

BEN STANSALL, AFP/GETTY IMAGES British Prime Minister David Cameron is set to leave office.

JULIEN WARNAND, EUROPEAN PRESSPHOTO AGENCY Prime Minister David Cameron says he will leave office by October, setting off a race among Conservatives to replace him.