The UK Independence Party has refused to identify the source of its projected £2 million European election fund after new figures from the Electoral Commission showed donor income of just £250,000 in the first three months of this year.

The figures showed that the Tories received £2.6 million in the first three months of this year, compared with £2.5 million received by Labour and £950,000 by the Liberal Democrats.

Of the Conservatives' cash, nearly £19,000 came from Rupert Murdoch's News International.