The German chancellor delivered a vague but pointed warning to British leaders on Wednesday amid questions over how the UK's divorce from the EU will impact the free movement of people across Europe.

Speaking at an event for labor union officials in Berlin, Merkel said that "if the British government says that free movement of people is no longer valid, that will have its price in relations with Britain."

Merkel said that if Britain were to limit the number of EU citizens allowed into the country to only 100,000 or 200,000, for example, "we would have to think about what obstacle we create from the European side to compensate that." She was quick to say, however, that such a plan wasn't meant to be "malicious."

Freedom of movement between the UK and the EU remains a central issue in negotiations over Brexit, whose supporters often pointed to migration as one of the most compelling reasons to leave the 28-member bloc.

Farage tells EU to 'grow up'

Also on Wednesday, MEP Nigel Farage of UKIP, the right-wing populist and euroskeptic party that led the drive to leave the EU, warned his colleagues in the EU Parliament that the UK would walk away from the table if Brussels continued its "bullying" behavior.

"In any other part of the civilized world frankly that behavior would be considered to be bloody rude and the act of a bully," Farage said. "Well I'll tell you something, your attempt to bully the Brits through these negotiations is not working, sixty-eight percent now of the British people want Brexit to happen."

Farage was responding to alleged leaks following a meeting between May and EU Commision President Jean-Claude Juncker.

"Either we get some grown up, reasonable demands from the European Union or the United Kingdom will be forced to walk away before the end of this year," he said.

blc/rc (AP, Reuters, dpa)