Harriet Harman has expressed “regret” that a civil rights organisation she used to work for had links with a prominent pro-paedophile campaign group in the 1970s.
The Labour deputy leader has vigorously defended her actions as the legal officer of the National Council for Civil Liberties (NCCL), which granted “affiliate” status to the Paedophile Information Exchange (PIE) in 1975, before Ms Harman had joined.
Ms Harman has accused the Daily Mail of running a “politically-motivated smear campaign” after it ran a series of stories, which called for Ms Harman, her MP husband Jack Dromey and former Health Secretary Patricia Hewitt to explain their connections to the PIE while holding key roles in the NCCL.
Breaking her silence on Monday, Ms Harman told BBC Two’s Newsnight programme that she stood by her actions "all the way through" her time at the NCCL when PIE was "challenged" and "pushed aside".
She repeatedly sidestepped questions over whether it had been a mistake to allow PIE to be affiliated to the NCCL, saying that anybody could join "simply by paying a fee".
In a fresh statement on Tuesday, a spokeswoman for Ms Harman said: "She regrets the existence of PIE and she regrets their involvement with NCCL before she joined, although it was immaterial to her work.
"She stands by the statement from yesterday and she is certainly not going to apologise to the Daily Mail."
In her Newsnight interview, Ms Harman repeatedly declined to accept that it had been a mistake for any link to have been allowed between the NCCL and PIE.
"On the basis that it has created, somehow, a sense that NCCL's work was therefore tainted by them, yes, obviously that is a very unfortunate inference to happen," she said.
"It is not the case that my work when I was at NCCL was influenced by PIE, was apologising for paedophilia, or colluding with paedophilia - that is an unfair inference and it's a smear."
Asked why she would not say it had been wrong, she told the programme: "Because they were challenged and they were pushed aside from their views having any influence on NCCL."
The senior Labour politician said the Daily Mail was “aggressively trying to completely reshape the facts of a situation 30 years ago".
"It is ironic that they are accusing me of supporting indecency in relation to children when they themselves are not above producing photographs of very young girls, titivating photographs, in bikinis,” she said.
"I stand by what I was doing at NCCL and I stand by what I have done all the way through."
She added: "I think if there is anybody who has over the years supported indecency it is much more the Daily Mail than it is me and that's the frank truth of it."
The newspaper has accused Ms Harman and Mr Dromey of issuing statements "full of pedantry and obfuscation", which failed to answer central allegations and denied others it had not made.
"For 10 weeks now the Mail has repeatedly asked three leading Labour figures to answer questions about the involvement of the NCCL, a body in which they played leading roles, with a vile paedophile group whose actions are currently being investigated by the police," a spokesman said in a statement issued before Tuesday's expression of "regret".
"More pertinently they have failed to utter a word of contrition or sorrow about the NCCL's closeness to the notorious Paedophile Information Exchange, an organisation that validated the activities of a monster like Jimmy Savile. Nor do they utter a word of apology to the victims of PIE."
Patricia Hewett has yet to comment on the story.
Additional reporting by Press Association