Late last year the Liberal Democrats claimed that almost 10% of British Army personnel are classified as unfit for frontline duty. Mr Campbell said: "Britain's armed forces are already undermanned and overstretched. If 10% of the Army is unfit, this puts further pressure on other servicemen and women."

A prominent critic of Robin Cook's 'ethical foreign policy' following the controversy over continuing arms sales to Indonesia, he has, however, supported the UK intervention in Sierra Leone.

In January this year Robin Cook and Menzies Campbell said in a joint article that Labour's links with the Liberal Democrats must be strengthened to prevent the traditional two-party system damaging Britain's future.

Despite a high profile in and out of the House of Commons, he decided not to contest the party leadership following the departure of Sir Paddy Ashdown.

A QC before entering politics, in the 1960s he was a celebrated athlete, holding the British 100 metres sprint title.