The dramatic demise of Des Browne as Secretary of State for Defence and Scotland has shaken the Service chiefs who had tried to impress on Downing Street that it was important to have ministerial continuity during a period of key decisions over Iraq, Afghanistan and equipment projects.

The general feeling inside the Ministry of Defence up until very recently was that the message had got through to Downing Street and that Mr Browne would remain as the Secretary of State.

Mr Browne, however, had made it clear to the Prime Minister, according to officials close to the former Defence Secretary, that he no longer felt it was appropriate to have two portfolios: defence and Scotland.

The officials said that Mr Browne had told the Prime Minister that the Armed Forces did not feel it was right for the Defence Secretary to have to share his ministerial time with Scottish affairs responsibilities.

He told Mr Brown that he would prefer to keep defence but give up Scotland. The Prime Minister, however, offered him Scotland and Northern Ireland as a joint ministerial package. Mr Browne rejected the offer and his Cabinet career came to an end.

The original decision by the Prime Minister to combine defence with Scotland not only created an unfavourable impression with troops in Iraq and Afghanistan and among Nato partners, it also put huge pressures on Mr Browne. Officials said that the only way he could devote sufficient time to both jobs was to spend any spare hours he had in the evenings and at the weekends on Scottish matters.

The Times estimated, on the basis of Freedom of Information requests to the MoD, that Mr Browne was having to spend between 15 and 20 per cent of his time on Scottish matters, including visits to Scotland, heading up debates in the Commons and holding meetings with officials from the Scottish Office.

He quickly became known as “two-jobs Des”, not just by the Opposition but by Service personnel. Troops did not take kindly to the fact that the man who was supposed to be making life-and-death decisions on behalf of the Armed Forces was unable to devote his whole time to defence.

There were reports that Mr Browne’s health was suffering because of the pressure of the work, although recently, according to his close officials, he had started going to the gym for work-outs and was beginning to lose weight.

The military chiefs had been keen to keep Mr Browne because defence is a big and complicated brief, and now they and senior civil servants will have to arrange a whole number of visits for the new Defence Secretary to Iraq, Afghanistan and all the other key areas where British troops are serving to familiarise him with what the Forces are doing.

Two issues, in particular, will now have to be placed in the hands of the new man, John Hutton — the drawdown timetable for Britain’s troop presence in southern Iraq, and the key decisions required on the equipment programme which, in its present form, the MoD can no longer afford.

Before he left the MoD yesterday, Mr Browne carried out one final task, signing a formal submission to the Treasury asking for £500 million from reserve funds to pay for the purchase of 600 armoured vehicles for troops in Afghanistan.

Mr Browne had been personally involved in fighting for the huge off-the-shelf order and he was determined to ensure that his signature was attached to the documentation, and not Mr Hutton, his incoming successor at the MoD.

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