One in four of the front-line ground troops being deployed to Iraq and Afghanistan this autumn will be Scottish, The Herald can reveal.

The Scots Guards and the Royal Scots Borderers (1st battalion, Royal Regiment of Scotland) are to make up half of the infantry strength in Basra from November, while a company of Scots Guards and a reinforced platoon of the part-time 52nd Lowland's 6th battalion go to Helmand and Kabul.

The Scottish contingents amount to more than one-quarter of the eight major infantry units serving in the two war zones.

News of their deployment comes less than a week after a leaked memo from General Sir Richard Dannatt, the chief of the general staff, warned that the Army has almost run out of troops to defend the country or reinforce existing garrisons.

The memo said all available soldiers apart from a rapid deployment battalion of 500 men were now committed to operations, recovering from them, or training to replace those already abroad.

It also follows a period in which seven British soldiers have been killed in and around Basra since the start of July - four of them in the past week from mortar or rocket fire.

The armed forces have only a "limited" ability to take on fresh operations on top of their commitments in Iraq and Afghanistan, the Ministry of Defence acknowledged yesterday.

In its annual report, the MoD said that it had taken a "deliberate risk" with the readiness of the forces to mount new operations in order to sustain the missions in Iraq and Afghanistan.

The MoD annual report said that as a result of the Afghan and Iraq campaigns, since 2002 the forces had been operating "significantly beyond the level they are resourced and structured to sustain" over the medium to long term.

"In order to support and sustain current operations the department has taken deliberate risk against achieving the public service agreement (PSA) readiness target to undertake future