Dr Williams says it is vital that politics is not totally devalued as a calling
The Archbishop of Canterbury has warned the "systematic humiliation" of MPs over their expenses is a threat to democracy in Britain.
Dr Rowan Williams said the daily press revelations could erode people's confidence in the political system.
Writing in The Times, he said: "Many will now be wondering whether the point has not been adequately made."
His comments came as the ex-SAS officer who gave the expenses data to the Daily Telegraph defended their publication.
John Wick, who passed the details on from an anonymous source, said he had "no regrets" about exposing the expenses system's "rotten core".
"Parliament will be a better place, society will be a better place," he added.
In his article, Dr Williams agreed that action was needed to restore confidence in the political system and that the "no rules were broken" mentality that featured in many MPs' responses represented a "basic problem" in contemporary moral thinking.
But he argued the point had now been made and that further revelations could have a damaging effect.
"The continuing systematic humiliation of politicians itself threatens to carry a heavy price in terms of our ability to salvage some confidence in our democracy," he said.
Matthew Parris of the Times says a "lynch mob mentality" seems to have gripped people
It was important to preserve the idea that serving as a politician could be what he described as "a calling worthy of the most generous instincts", he added.
Times columnist and former MP Matthew Parris told the BBC that although he did not think there should be a press "ceasefire or amnesty" with regard to expenses, it was important the situation was assessed rationally.
"I do think we need to stand back a little, pause, draw breath and try to distinguish between the vast majority of Members of Parliament - many of whom have pushed things a bit further perhaps than they should have within the rules... and just a few of whom are absolutely crooks," he said.
Aiming "general kicks" at all MPs regardless of their behaviour was "bad for Parliament, bad for democracy and bad for us", he added.
But Labour peer Lord Campbell Savours, one of the original campaigners for the Freedom of Information Act, said the archbishop's claims that the expenses controversy threatened democracy were "rubbish".
"It's not undermining democracy at all. It's not threatening democracy," he said. "It will lead to a change in the expenses system in the House of Commons, which many Members of Parliament would welcome."
John Wick said he felt compelled to release the expenses information
Dr Williams voiced his fears after Tory MP Nadine Dorries complained of a "McCarthy-style witch-hunt" of MPs and suggested someone might commit suicide because of the pressure.
Further allegations about Tory and Labour politicians' expenses were published in the Daily Telegraph on Saturday.
The paper reported that shadow business secretary Jonathan Djanogly claimed £5,000 for a set of automatic gates for his home and nearly £13,000 for gardening.
Mr Djanogly told the BBC he had acted "credibly and reasonably", but had decided to repay £25,000 of the £77,104 he has claimed in total because of public anger.
The paper also accused Northern Ireland Minister Paul Goggins of allowing a university friend to live rent-free in a home paid for by the taxpayer.
But Mr Goggins told the BBC the arrangements were based on a "30-year friendship" with Chris Bain and due to the fact that Mr Bain had been the joint owner of the property for six years between 1997 and 2003.
Conservative MP Bernard Jenkin also reportedly used £50,000 in expenses to pay his sister-in-law rent for the property he uses as his constituency home.
Mr Jenkin told the BBC he was "devastated" by the criticism and that there was no suggestion of property speculation and that he was just paying "an honest and reasonable rent".
The paper also turned the spotlight on Labour MP Khalid Mahmood for allegedly claiming £1,350 for a stay in a five-star west London hotel with his girlfriend.
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