In language reminiscent of his vow of loyalty to Lady Thatcher, he insisted: 'There are no circumstances in which I would stand against John Major.
'John Major is going to lead us into the next election, and people know that my forecast is that we shall win with a majority of 60,' he said on Channel 4's A Week in Politics.
Mr Heseltine, President of the Board of Trade, concurred with Home Secretary Michael Howard that John Major would hand over to a younger man.
But, offered the opportunity to accept that he would never make it to 10 Downing Street, Mr Heseltine declined.
'I am not using those words because nobody knows what the absolute extreme and unforeseen circumstances can be.'
Asked, in an interview in the Sunday Express, about reports of challenges to his leadership Mr Major said: 'I am pretty unmoved by them. I have lived through them for the last two years. It has not affected what I think or what I do or how handled the Government in those two years/