This challenge is a cowardly machination, say the Tories

They sought to portray the Foreign Secretary as "cowardly" for not being bolder in challenging Gordon Brown, despite Mr Miliband's decision to lay out his vision to save the Labour Party which electrified talk of moves against the Prime Minister.

Sources let it be known that David Cameron had not been impressed by Mr Miliband's machinations, suggesting his behaviour was dishonourable.

But the Conservative attack on Mr Miliband will be seen by some MPs as a sign that they fear the Foreign Secretary more than the current Prime Minister.

Mr Miliband may be a more difficult target for the Tories who have portrayed Mr Brown as the past political generation and his personal poll ratings have plunged.

Shadow chancellor George Osborne today claimed that Labour is now so divided that it cannot properly govern the country and called on Mr Brown to call a general election now.

He even accused the PM of driving up the cost of foreign holidays.

Mr Osborne said: "Britain needs leadership in these difficult times. "There are tough decisions to be taken on helping families with the cost of living, bringing stability to public finances and tackling our broken society. We need a Government that's on our side, not at each other's throats."

He questioned, in an article in The Sun, whether senior Labour figures were distracted from their Government duties by a possible party leadership contest.

Mr Osborne added: " We are paying an unfair price for Gordon Brown's mistakes. Families taking a holiday in Europe will notice how expensive it is.That's because the pound has fallen on world markets as Government incompetence rises."