A split between the Conservative and Liberal Democrat government partners over Prime Minister David Cameron's European veto that isolated Britain from the other 26 EU countries will not put the coalition at risk, a senior Liberal Democrat said on Monday.

Conservative Cameron's decision last week not to take part in an EU treaty change aimed at tightening fiscal rules for the bloc created the biggest rift in his coalition since he took power in May 2010.

This doesn't threaten the coalition. The coalition was formed to deal with the enormous economic problems that we inherited as a country, said treasury minister Danny Alexander, a Liberal Democrat.

That task is the central task of this government. It's a task that will continue over the full five years until 2015 when there will be another general election.

(Reporting by Michael Holden; editing by Keith Weir)