As with any military operation, those forces assigned to operations in Afghanistan are subject to periodic rotation. Preparations for the next such rotation are underway now. These build on the progress we have made in Helmand in the six months since 10 July 2006 when I informed the House of our current deployments in Afghanistan. Our military effort is a part of the United Nations' authorised and NATO-led International Security Assistance Force (ISAF).

The UK will hand over command of the ISAF on 4 February 2007 and the Command Group of the Allied Rapid Reaction Corps, will then return to their base at Rheindalen. In their place, the UK will provide some 140 personnel for the new ISAF Headquarters now forming in Kabul, leading to an overall reduction of the UK presence in the city of around 500 troops.

In the South, 3 Commando Brigade, Royal Marines, will complete their tour in April 2007. They will be replaced by units drawn principally from 12 Mechanised Brigade. We have also decided to maintain until April 2009 some capabilities already deployed, including the Harrier GR7/GR9s, the Apache Attack Helicopters, Viking all-terrain vehicles, and Royal Engineers to support reconstruction activities. By the late summer, personnel numbers in Southern Afghanistan should settle at around 5,800.

The principal units to deploy are: the Brigade Headquarters and its Signal Squadron, the Light Dragoons, the 1st Battalion The Grenadier Guards, the 1st Battalion The Royal Anglian Regiment, The 1st Battalion The Worcestershire and Sherwood Foresters, 26 Engineer Regiment Royal Engineers, 19 Regiment Royal Artillery, 2 Signal Regiment Royal Signals, 4 Logistic Support Regiment Royal Logistic Corps, and 4 General Support Medical Regiment Royal Army Medical Corps.

Elements of other units are also deploying to provide niche capabilities. These include: the Armoured Support Group of the Royal Marines, the Light Dragoons, the Second Royal Tank Regiment; 3 Regiment, Army Air Corps; 9 Regiment, Army Air Corps; 1 (Fighter), IV (Army Co-Operation), 18, 24, 27, 30, 47 and 70 Squadrons of the Royal Air Force, 3, 5 and 7 Force Protection Wing Headquarters, Royal Air Force, and 2, 51 and 15 Squadrons of the Royal Air Force Regiment.

As with previous deployments to Afghanistan, there will be a requirement to deploy reservists to serve in theatre. Current plans indicate that around 600 Call Out Notices are to be served on individual reservists in order to fill approximately 420 posts (including nine Sponsored Reserve).

All military operations are subject to regular review. Work on the balance of NATO's commitment in Afghanistan is underway and I intend to discuss this with my NATO colleagues when we next meet on 8-9 February. I shall keep the House informed of progress and any implications for the UK's own force structures.