Britain must pay a heavy price for opting to leave the EU to avoid the risk of contagion, Francois Hollande has said. The remarks by the French President echoed those made by his German counterpart, Angela Merkel, who warned that Britain cannot have full access to the bloc's single market without "signing up to the four freedoms."

Speaking at a the Jacques Delors Institute in Paris yesterday (6 October), Hollande said: "There must be a threat, there must be a risk, there must be a price, otherwise we will be in negotiations that will not end well and, inevitably, will have economic and human consequences."

Addressing 150 guests, he added: "The UK has decided to do a Brexit, I believe even a hard Brexit. Well, then we must go all the way through the UK's willingness to leave the EU. We have to have this firmness."

Last week British Prime Minister Theresa May said she would trigger divorce proceedings from the EU [formally known as Article 50] by the end of March 2017. This would put the UK on course to leave the bloc in 2019.

Speaking at the Conservative Party Conference in Birmingham, May offered an unwavering stance on immigration control. "We're going to be a fully independent sovereign country that is no longer part of a political union with supranational institutions that can override national parliaments and courts," said May.

"And that means we're going once more to have the freedom to make our own decisions on a whole host of different matters, from the way we label our food to the way in which we choose to control immigration," added May.

But Hollande was uncompromising in his retort, signalling that Britain could not have its cake and eat it. "Today, Britain wants to leave, but does not want to pay anything. That is not possible," he said.

"We must be firm or we will jeopardise the very principles of the EU," the French leader added, warning that other Member States may also follow suit if they get the idea that "they can get the benefits without having the inconveniences and the rules."