Tony Blair should have prayed with US President George Bush before they decided to launch the war in Iraq, the Archbishop of Canterbury has said.
Although the two men are devout Christians, Mr Blair famously told interviewer Jeremy Paxman that he and Mr Bush did not pray together in the run-up to war.
Dr Rowan Williams said that if they had prayed to God about the war, they may well have received a different answer from the one they wanted.
Dr Williams' comments come a day after a speech in which he bemoaned the lack of a moral basis to modern politics, voicing concern at the "draining away of any residual notion that the state itself has or should have a moral foundation".
"The more politics looks like a form of management rather than an engine of positive and morally desirable change, the more energy it loses," he said.
He told Newsnight on Wednesday night that he did not expect governments to talk about religion, but did think they should leave open a space for religious ideas to influence public debate and policy.
In response to former Downing Street media chief Alastair Campbell's often-quoted remark that "we don't do God", the Archbishop said: "I think Prime Ministers as individuals ought to 'do God', because I think everybody ought to.
"I don't expect Government to be talking religion. I do expect Government to be giving space and opportunity for the kind of moral discussion informed by religion, as by many other strands of humanistic thought."
Dr Williams said he did not think Mr Blair's Christianity was a cause of unease among voters, except in the context of the Iraq War, when some people thought the PM was signing up to Mr Bush's "rather crusading attitude".
"Suddenly, his religious convictions became awkward and embarrassing to him and embarrassing to everybody," he said.
