A TORY plan to unveil a former Army chief and arch-Gordon Brown critic as a defence adviser backfired – when a senior Conservative called it a "gimmick".

Chris Grayling, the “Shadow Minister for Liverpool”, was left-red-faced after mistakenly believing General Sir Richard Dannatt was being appointed by the Government, not his own party.

The Shadow Home Secretary told an interviewer: "I hope that this isn't a political gimmick. We've seen too many appointments from this government of external people, where it has all been about Gordon Brown's PR."

The gaffe added to the discomfort of Conservative leader David Cameron, who – prior to the leak – had been poised to unveil the general ahead of his keynote close-of-conference speech today.

Now General Dannatt is expected to be given a seat in the House of Lords – and may become a minister in any future Tory government.

The move is controversial because the general has waged a bitter war of words with Downing Street over its conduct of the war in Afghanistan.

The general's switch to advising the Conservatives will surprise many, because it turns an independent critic into a partisan political figure, inevitably downgrading his criticisms.

Meanwhile, today, Mr Cameron will try to strike a more optimistic note after a week in which the Conservatives have focused on "painful cuts" to come.

He will tell the conference: "Yes, there is a steep climb ahead, but I tell you this: the view from the summit will be worth it."