Anne McGuire, Labour's Shadow Minister for Disabled People, responding to the latest claims surrounding the IT firm Atos, said:
"These revelations raise extremely serious questions over the £540m PIP contracts. There is now clear evidence that Atos won a £400m contract with a bid that was misleading.
"There must be an immediate investigation because the integrity of the entire process is now in serious doubt. Ministers must now explain exactly how these claims got through unchecked."