In a report to be published on Thursday, the committee of lower House of Commons MPs will criticise what is seen as the government's failure to equip troops with what they need.
According to The Guardian, some British soldiers have been bolting makeshift panels on to the side doors of supplied Land Rovers and the front of trucks to try to protect themselves from roadside bombs and grenades.
Defence Secretary Des Browne last month said the army would get about 300 new, tougher armoured vehicles, but they wouldn't be available until the end of the year.
The report follows criticism of the MoD by an Army Board of Inquiry last month which said that the killing of a British tank commander by "friendly fire" in Iraq in March 2003 could have been prevented by five factors.
One of those was the fact that he had been ordered to give up his enhanced combat body armour three days before going into battle.