Addressing a briefing on lessons learnt from the Iraq war Lieutenant-General Michael Moseley said that in 2002 and early 2003 allied aircraft flew 21,736 sorties, dropping more than 600 bombs on 391 “carefully selected targets” before the war officially started.

The nine months of allied raids “laid the foundations” for the allied victory, Moseley said. They ensured that allied forces did not have to start the war with a protracted bombardment of Iraqi positions.

If those raids exceeded the need to maintain security in the no-fly zones of southern and northern Iraq, they would leave President George W Bush and Tony Blair vulnerable to allegations that they had acted illegally.

Moseley’s remarks have emerged after reports in The Sunday Times that showed an increase in allied bombing in southern Iraq was described in leaked minutes of a meeting of the war cabinet as “spikes of activity to put pressure on the regime”.

Moseley told the briefing at Nellis airbase in Nebraska on July 17, 2003, that the raids took place under cover of patrols of the southern no-fly zone; their purpose was ostensibly to protect the ethnic minorities.

A leaked memo previously disclosed by The Sunday Times, detailing a meeting chaired by the prime minister and attended by Jack Straw, the foreign secretary, Geoff Hoon, the then defence secretary, and Admiral Sir Michael Boyce, chief of defence staff, indicated that the US was carrying out the bombing.

But Moseley’s remarks, and figures for the amount of bombs dropped in southern Iraq during 2002, indicate that the RAF was taking as large a part in the bombing as American aircraft.

Details of the Moseley briefing come amid rising concern in the US at the war. A new poll shows 60% of Americans now believe it was a mistake.