How the Conservatives will handle Ed Miliband

The Conservatives will play the patriotic card against Ed Miliband, claiming that he is betraying the national interest by refusing to spell out how Labour would tackle the £155bn deficit.

But at their conference in Birmingham, which starts on Sunday, the Tories will avoid personal attacks on him, knowing that strident assaults on a leader barely known by the public could be counterproductive. "We will stick to the substance," one Tory insider said. In his speech on Tuesday, Mr Miliband said he was "serious" about the deficit. The Tories, who immediately dubbed him "a man without a plan", say he will have to do better than that. Every time he criticises a Coalition spending cut, they will ask him: "What would you cut?"

David Cameron rehearsed his party's lines yesterday: "To say what Ed is saying, and forget about the deficit because it's somehow pessimistic to talk about it, that would be completely betraying the country."

Labour's policies will not emerge overnight and Mr Miliband may keep the Tories waiting for a definitive Labour approach to the deficit. "We are not going to produce an alternative spending review," one aide said.

However, Mr Miliband will inevitably be defined by his response to "events" such as the strikes planned by trade unions against the cuts. If he does veer left, the Tories will pounce. If he sticks to the centre ground, they will not make "Red Ed" attacks on him that lack credibility. Mr Cameron knows that Britain's Tory-dominated newspapers will do the dirty work anyway.