In response to reports yesterday that he had attended meetings with political advisers during which a leadership challenge was discussed, Mr Portillo said: 'Anyone seeking to promote my name does so against my wishes.'
A Sunday newspaper reported that Mr Portillo had been involved with a think-tank associated with Mr Hart, which was designed to promote his aspirations as party leader. A leaked memo to the minister explains that the think-tank would aim to be perceived as independent and would not identify Mr Portillo as its focal point.
Mr Hart, it has also emerged, loans an office to one of Mr Portillo's political advisers, Alison Broom. It is not clear whether or not he also pays her for consultancy services.
The reappearance of David Hart, one of the most extreme figures on the Tory right-wing during the 1980s, may cause concern among more moderate members of the party. A number of Conservative MPs have already warned Mr Portillo that unless he ends his association they will not support him in any leadership bid. The fact that the two men have now been linked to a leadership campaign will redouble those concerns.
Many thought that Mr Hart's period of influence had passed with the fall of Mrs Thatcher, now Baroness Thatcher. But he has remained active within the Tory party. He is friendly with several Cabinet ministers and last year it was diclosed that Malcolm Rifkind, the Secretary of State for Defence, had hired him as a political adviser. But he is particularly close to Mr Portillo, 40, whom he claims to have known for 20 years. He is understood to have drafted some parts of his speech to the party conference last year.
Mr Hart rose to political prominence as the man behind the far- right Committee for a Free Britain during the 1980s, and as one of Mrs Thatcher's closest confidantes.
It was the 1984 miners' strike that brought him into the public eye, during which he had a secretive and, many felt, sinister role as link man between Downing Street and the Coal Board. He has been linked both to MI5 and to the CIA. In her memoirs, Baroness Thatcher praised Mr Hart for his help in defeating the miners.
Mr Hart was not available for comment yesterday.