The Archbishop of Canterbury Dr Rowan Williams has suggested the aftermath of the Iraq war has resulted in a loss of trust in the nation's political system.
Dr Rowan Williams questioned the moral legitimacy of the Iraq war
Dr Williams hinted the UK's "political health" has been damaged by failure to find weapons of mass destruction.
Admitting error might be one way to restore trust, he said in a sermon delivered in Cambridge on Tuesday.
Downing Street said Dr Williams' views on the war were well known and it had nothing further to add.
The archbishop's remarks were addressed to the congregation at St Benet's Church in Cambridge.
He spoke on the theme of Christian obedience in the commemoration sermon.
He warned Christians should not expect an "impossible" standard of corporate selflessness from government.
But, he said, part of the "continuing damage" to the nation's political health was to do with concern over what had really driven events on the international scene.
Dr Williams said claims on the political loyalty of
Christians had to do with a "demonstrable attention to truth, even unwelcome truth".
He said: "There were things government believed it knew and claimed to know on a privileged basis which, it emerged, were anything but certain - there were things which regional experts and others knew which seemed not to have received attention."
He added: "The evidence suggests to many that obedience to a complex truth suffered from a sense of urgency that made attention harder."
The archbishop said restoring trust lay in the government's openness to accountability, the freedom to think again and willingness to admit error or miscalculation.
He said large-scale campaigns of public disobedience against governments were confined to "serious and lasting injustice".
"It is more that we face a general weakening of trust in the political system of our nation," he said.
BBC religious correspondent Robert Piggott said Dr Williams had questioned the moral legitimacy of the war in Iraq from the start.
He said Dr Williams' latest sermon had been "clearly aimed" at the government and its handling of the war and its aftermath.
Labour MP Meg Munn, a Christian Socialist Movement member, told BBC Radio 4's Today programme the government knew there were "issues of trust."
"But I do not agree at all with the view the government has repressed criticism," she added.
"The situation over Iraq - and indeed over many, many issues - is there has been considerably more debate than has been the case in the past."
Ms Munn told Today: "We live in a democracy with a very robust media.
"People did demonstrate about the issue of Iraq, there was lots of discussion, and that is how I would like to see our country continue to run."