Norfolk MP Norman Lamb avoided giving a direct answer today when asked if the prime minister had done the right thing in using Britain's veto at the EU summit in Brussels last week.

He held back from giving full support for Mr Cameron when asked in EDP and BBC interviews about the veto. And he thereby underlined the deep frustration in his party about the outcome of the summit in which the prime minister was alone in refusing to endorse a new treaty to shore up the beleaguered Eurozone.

Mr Lamb also followed the example of his party leader, deputy prime minister Nick Clegg, however, in refusing publicly to blame the prime minister for what had happened and for Britain's isolation at and after the summit.

The two coalition parties had 'agreed the terms' Mr Cameron took to Brussels, he said, and 'they were reasonable'. It was 'a great pity that they were not accepted'.

The prime minister had been 'caught in a very difficult position' he continued, and had become 'trapped between the intransigence of the French and the Tory Right'.

Mr Lamb is the chief parliamentary adviser to the deputy prime minister