Britain must trigger the Article 50 clause that allows talks to commence on its exit from the European Union urgently, France's foreign minister has said.
Speaking after a meeting of foreign ministers from the six EU founding member states - Germany, France, Belgium, Italy, the Netherlands and Luxembourg - in Berlin, after the UK’s historic vote to leave, Jean-Marc Ayrault warned against Britain playing a "cat and mouse" game.
"Of course a new (British) prime minister must be appointed, that will probably require a few days but this is quite urgent," he added.
"It's in Britain's interest and in the interest of Europeans not to have a period of uncertainty that would have financial consequences, and that could have economic and political consequences," he added.
German Foreign Minister Frank-Walter Steinmeierer, who had invited his counterparts to the hastily convened talks, said he did not think Britain was "setting an example for Europe".
But Mr Steinmeierer added that there is "no reason for hysteria on the one side or paralysed shock on the other side".
Meanwhile, Belgium's foreign minister Didier Reynders said Europe must deliver answers on immigration, security and jobs.
Dutch counterpart Bert Koenders added that Europe could not accept a political vacuum. "This will not be business as usual," he said.
But Vote Leave campaign director Dominic Cummings said it was "unthinkable" to invoke Article 50 before a new Prime Minister was in place.
Writing on Twitter, Mr Cummings said: "David Cameron was quite right. New PM will need to analyse options and have informal talks."