Former ambassadors, senior military figures and a bishop were among 44 signatories of an open letter to Prime Minister Tony Blair today calling for an inquiry into civilian deaths in Iraq.

The former Assistant Chief of Defence Staff Lord Garden put his name to the appeal, alongside retired General Sir Hugh Beach, ex-ambassador to Iraq Sir Stephen Egerton and the Bishop of Coventry, Colin Bennetts.

The letter follows a study published in The Lancet in October which estimated the number of excess deaths in Iraq since the outbreak of hostilities in March last year at 98,000.

The study, by a team of American and Iraqi researchers, said most of the additional deaths were women and children, and said the risk of violent death was higher after the war than before.

Today’s letter urged Mr Blair to set up an independent inquiry to establish with the greatest possible accuracy the number of people killed or injured in Iraq, along with the reason for the casualties.

While rejecting the Lancet figures, the Government has offered no estimate of its own of the number of deaths resulting from the war and occupation, the signatories noted.

“As you know, your Government is obliged under international humanitarian law to protect the civilian population during military operations in Iraq, and you have consistently promised to do so,” said the letter.

“However, without counting the dead and injured, no-one can know whether Britain and its coalition partners are meeting these obligations.”

The publication of the letter marked the launch of a new joint campaign www.countthecasualties.org.uk by health charity Medact and the Iraq Body Count project, who are challenging the Government to count casualties systematically, rather than simply rejecting independent assessments as “unreliable”.

Co-founder of Iraq Body Count John Sloboda said: “Having made no effort to count Iraqi casualties at all, the British Government now says that reliable figures are not available.

“We know from our work and the research of others that information from Iraqi hospital, mortuary and other official sources is available and this should be combined with media reports, military contact data and active on-the-ground research to establish the most accurate figures possible.

“No figures in a war zone are going to be perfect – but that’s no excuse for not trying.”

Medact director Mike Rowson said: “We need casualty estimates to assess the effect of weaponry on the population and to plan health care for the injured. Without information, everyone is working in the dark.

“The overstretched Iraqi health system should not be left to do this job alone. Britain and its coalition partners have a responsibility to commission and resource this work themselves.”

Other signatories to today’s letter included the secretary general of the Muslim Council of Britain Iqbal Sacranie, human rights campaigner Bianca Jagger, writer Harold Pinter and former ambassadors Oliver Miles, Robin Kealy, Sir Brian Barder, Sir David Ratford, as well as a number of eminent health professionals and academics.

Foreign Secretary Jack Straw last month told the House of Commons that the Government believed the most accurate data came from the Iraqi Ministry of Health, which estimated that 3,853 civilians were killed and 15,517 injured between April and October 2004.