Amid the snow capped Alps of Switzerland, the EU tried to present a united front at the World Economic Forum in Davos after Britain threatened to leave the economic bloc.

EU leaders played down concerns of a rift following British Prime Minister David Cameron's pledge on Wednesday to hold a UK referendum on EU membership if re-elected.

Boris Johnson, Mayor of London, said the British public would likely vote to stay.

SOUNDBITE (English) BORIS JOHNSON, MAYOR OF LONDON:

"If you ask me where is Britain going to end up I will lay you any money at all, if we can get a decent deal which I think is very likely because our friends and partners will want to keep Britain in - if we can get a decent deal then I have no doubt at all that the British people, who basically in their hearts want to be part of the European Trading area, they want to be part of the common marker, we're a European country, they will vote to stay in."

German Chancellor Angela Merkel has set out a very different vision of Europe to that of Cameron, but Swedish Prime Minister Frederik Reinfeldt says it's the nature of the union for there to be some disagreements.

(SOUNDBITE) (English) FREDERIK REINFELDT, SWEDISH PRIME MINISTER:

"I've been in the European Council now for more than six years and there are always differences. I think the idea that the European cooperation is that we can respect this and work together."

The four day World Economic Forum in Davos that has brought together more than 1,500 business leaders and dozens of heads of state concludes Saturday.