Carol Thatcher aide: This is BBC vendetta

Her agent pointed the finger at a member of the production team on BBC's The One Show and suggested that it was part of a vendetta against Baroness Thatcher's daughter.

Comedian Jo Brand, who was a guest on the show, denied that it was her.

The 55-year-old daughter of the former prime minister was axed by the corporation after she refused to apologise for using the term while describing black tennis player Gael Monfils.

Thatcher, a roving reporter for the programme, made her comments during a post-show conversation with presenter Adrian Chiles and several guests including Brand.

Today Thatcher's agent Ali Gunn, asked on Talksport if she believed that this is a personal campaign against Thatcher, said: "That's what I believe, yes. It has been condoned by the producers of the BBC who haven't acted to discipline that member of staff."

Ms Gunn said: "This was a private conversation held in private, amongst individuals in the green room after she Carol Thatcher had been on The One Show. At the time nobody objected to that conversation and I wasn't made aware of the conversation until Saturday morning ie 48 hours after the conversation had taken place."

She added: "We actually dispute the fact that the BBC has leaked this story, for whatever reason they feel fit I'm not sure. Obviously they know what their agenda is and there is certainly an agenda behind this.

"This comment was made in jest afterwards in the green room over a drink and no one objected to it at the time. I think it's absolutely outrageous that the BBC has condoned this leak."

She went on: "They haven't even disciplined the member of staff and frankly we issued a fulsome apology that was rejected."

Meanwhile, Tory peer Lord Tebbit weighed into the row, also suggesting the corporation was "taking revenge" on Thatcher's mother. He said: "It does seem very odd that Jonathan Ross can be back broadcasting having made obscene, insulting remarks on the air, and Carol Thatcher, who said something which is allegedly highly offensive but which I rather doubt was meant to be so, in private, should be banned. It is probably a bit of a way for the BBC to get back at Carol's mother."

Brand herself is at the centre of a police investigation over quips she made during Live At The Apollo. She joked that as a result of the British National Party's membership list being made public on the internet, she now knew the addresses where to send the "poo" through the post.

The following day, Simon Darby, the BNP's deputy leader, made an official complaint to police alleging that her comment had been an act of incitement to cause racial harassment