The government has rejected calls for the removal of Defence Secretary Geoff Hoon over the death of a soldier killed after handing back his body armour.
Hoon said some equipment did not arrive in time
Widow Samantha Roberts released her husband's audio diary which talks of how ill-equipped he was. She said Mr Hoon was to blame and should step down.
But Defence Minister Ivor Caplin said an inquiry was under way into the death and it was not a resignation issue.
The problem was "the odd glitch or shortcoming in our processes", he said.
Sgt Steve Roberts, shot dead in March during an attack by Iraqi dissidents, recorded an audio diary in which he called supplies to soldiers "a joke".
A preliminary Ministry of Defence report into the death of the 33-year-old 2nd Royal Tank Regiment soldier indicated that armour could have saved his life.
Mrs Roberts claimed he had been ordered to hand his own armour back so it could be given to British infantrymen in Iraq who were judged to be more at risk.
She told BBC Radio Five Live her husband and other soldiers were "deeply shocked" at the lack of equipment.
Mr Caplin said he regretted all the losses of service personnel in Iraq "in whatever way they lost their lives".
He told BBC News: "I don't think that when we've had the odd glitch or shortcoming in our processes that that is necessarily a matter for ministerial responsibility."
Conservative leader Michael Howard said the affair amounted to a "dereliction of duty" by the government and that Mr Hoon should take responsibility and step down.
Earlier, a government spokesman dismissed calls for Mr Hoon to resign.
Prime Minister Tony Blair expressed his sympathy and condolences for Mrs Roberts and said he "totally" understood her concerns.
Mrs Roberts was in the Commons on Tuesday to hear a debate in which Mr Hoon declined to go into the details of her husband's case.
He said enhanced body armour had been issued for as many troops as possible but some of the 38,000 sets sent did not reach units before the war began.
A report from the National Audit Office (NAO) last month concluded there had been problems with the supply of vital equipment but also praised the scale and speed of the military operation in Iraq.
Mr Hoon promised to keep Mrs Roberts informed of the investigation but she said she was "disgusted" and wanted him to resign.