Downing Street has defended its involvement in the row over the hospital treatment of a 94-year-old woman.

Speaking as the war of words over the case of Rose Addis intensified, Number 10 said it wanted to be on "the side of fairness".

The row was sparked by a series of Commons clashes between Tony Blair and Iain Duncan Smith over the elderly patient's treatment.

The Conservative leader accused the prime minister of lying when he rejected claims that Addis had been left for three days with blood on her hands and feet in the casualty department of the Whittington Hospital in north London.

Speaking on Thursday, the prime minister's spokesman said that Blair believed the hospital at the centre of the row had a right to defend itself against the "false" allegations.

But the Tories hit back, accusing Downing Street of a disgraceful breach of patient confidentiality during briefings to journalists.

The party's health spokesman, Dr Liam Fox, said it was "quite legitimate" for Duncan Smith to highlight the case at question time but questioned the government's actions following the exchange.

Number 10 denied it had revealed private details concerning any patient - stressing, however, that NHS trusts had a right to "rebut" any allegations of misconduct.

"The idea that we have breached patient confidentiality is nonsense," said a spokesman. "The reasons the cases were in the public domain in the first place was that relatives had gone to the newspapers. We were simply repeating statements that had been made by the trust concerned."

The latest exchange came as the hospital's chief, professor James Malone-Lee, said Duncan Smith's claims were "spiteful and defamatory".

Malone-Lee said the row was frightening and demoralising for the staff at his hospital. "I was horrified and I feel intensely angry, and my anger is being expressed on behalf of so many health service workers who must be intensely offended by this sort of behaviour," he said.

"To kick us around the floor of the Houses of Parliament in this ill-considered and badly-informed way is just not acceptable."

Blair told the Cabinet on Monday that he believed the latest row went to the heart of the division over public services.

"We are now engaged in a full-scale battle which is at the heart of this parliament - namely the future of public services," he said.

"It is an important argument and is one that the government will win. Fundamentally it is a question of dealing with a problem of decades of under investment and by increasing investment allied to reform or to cut investment and have tax cuts to allow people to buy services."

Acting chief executive of NHS Confederation, Nigel Edwards, criticised the political row, saying that it "does not help the families address their concerns, nor does it help the hospital to deal with the complaints that have been made."

"NHS organisations that find themselves in the middle of this type of problem must be allowed to defend themselves," he said.

"The proper place for this to be dealt with is through the NHS complaints procedure where all sides can be offered proper confidentiality and a robust process."