Amid an inquiry into the 2003 military invasion of Iraq, David Cameron, the sitting British Prime Minister, called for public pressure on former Prime Minister Tony Blair over his refusal to release letters sent to US President George W. Bush in the lead-up to war.

Blair was expected to testify before Downing Street's Chilcot Committee on Friday. Cameron, leader of the conservative faction in Britain's government, said he hoped the inquiry would be "as open and clear as possible."

The committee was recently told by Matthew Rycroft, Blair's former private secretary, that he'd written two different retellings of the communications between Blair and Bush, in order to obscure what really transpired.