London Mayor Boris Johnson has called on the UK to negotiate a new "pared-down relationship" with the European Union, according to BBC News.

Mr. Johnson said Britain should remain in the single market but pull out of the political union. The UK should form an "outer-tier" of the EU with countries like Norway and Switzerland, he said in a speech.

And a referendum should be held with the question: "Do you want to stay in the EU single market as renegotiated? Yes or No?"

He urged David Cameron to "maximize the benefits of EU membership and the single market without being kicked out" and insisted other EU countries would accept such a proposition.