Former Deputy Prime Minister Michael Heseltine is to stand down from Parliament at the next general election, he announced today.
Mr Heseltine said he had told the chairman of his constituency association at Henley, Oxfordshire of his decision yesterday.
"When a man's got to go, he's got to go," he added.
Mr Heseltine, a former Tory leadership contender, told BBC Radio 4's Today programme that he did not want to stay on the backbenches.
In what may be interpreted as a snub, he said he had not warned or consulted party leader William Hague before announcing his Commons retirement.
Mr Heseltine, who first entered the Commons 34 years ago, as MP for Tavistock, said there were "a number of reasons" for his departure.
"I'm really a rather very active sort of person and I'm not given to being a sort of backbench guy waiting for the whips' instructions," he said.
"I'm now chairman of the Haymarket Publishing Group, which is a very exciting company which is expanding worldwide.
"I've got this arboretum which I am a bit manic about. I want to write a book about that.
"And I just know that my own association needs a younger guy to get in there and do what I did in Tavistock in the sixties."
Mr Heseltine - dubbed Tarzan - famously walked out of Margaret Thatcher's Cabinet, sparking the Westland crisis.
But he rose to become deputy prime minister under her successor, John Major, after backing him in the leadership contest he had called while premier to silence his critics.
Mr Heseltine said: "I know that I will never serve in another Conservative government and I'm just not that good at sitting around."
He stressed that he had not had any disagreements with Mr Hague, apart from over Europe, and did not feel left behind by the party.
Explaining his decision, he said there were things he wanted to do "which are not compatible with being lobby fodder in the House of Commons.
"It's not fair to deceive my constituents to pretend that I am doing a full-time job for them when I am not."
But he confirmed he had not told the Tory leader of his decision, saying: "No I haven't told William. I will do so. To be honest about it, I felt that I wanted this to be something that came new, that there was no risk of any leaks."Reuse content