Tory peer Lord Biffen, who has died age 76, was respected across the political spectrum for his honesty and independence of mind.
Lord Biffen was a key member of the first Thatcher Cabinet
He was the one politician with whom Tony Blair said he would willingly share a desert island.
In an age when spin and political conformity were gaining ground, he held on to his principles - even if it meant the premature end of his Cabinet career.
He is best remembered for being described as "semi-detached" by Margaret Thatcher's spokesman Bernard Ingham for daring to suggest, in 1986, that she might not go on forever.
It was a label he learned to live with, even see as a badge of honour, but it tended to obscure his other achievements as a political sage and defender of the independence of the House of Commons.
The son of a Somerset tenant farmer, John Biffen was a grammar school boy, who won a scholarship to Jesus College, Cambridge.
He entered parliament in 1961, as the MP for Oswestry, later renamed North Shropshire.
But he was never content to meekly toe the party line, voting against incomes policy, Rhodesia sanctions and, above all, entry to the EEC.
As a result, he remained on the backbenches under the leadership of Edward Heath, an ardent Europhile with whom he enjoyed an uneasy relationship.
But he flourished under Heath's successor Margaret Thatcher, who appreciated his monetarist economic views - he had been a disciple of Enoch Powell in the 1950s and 1960s, sharing his free market beliefs.
Mrs Thatcher made him Chief Secretary to the Treasury in her first Cabinet - one of an inner circle of "dries" who would drive through the Thatcherite revolution in the teeth of opposition from the "wets" on the front bench.
He gained a reputation as a deep thinker, who avoided scoring easy points against his political opponents.
"I remember very vividly in Cabinet: by and large you know what people are going to say, because they are going to take the departmental brief, but you could never tell when he started to speak where his conclusion was going to be," Lord Heseltine recalls of his former colleague.
He was made trade minister and then leader of the House of Commons, a role in which he was said by political commentators - and even opponents - to have excelled.
But his commitment to hardline Thatcherite economics softened as the 1980s progressed, amid soaring unemployment.
When, in 1986, he called with characteristic frankness for a "balanced ticket" to fight the next general election, it was seized on by Thatcher's opponents as a sign he saw her as a vote loser.
"No one seriously supposes that the prime minister would be prime minister throughout the entire period of the next Parliament," he told Brian Walden in the 1986 Weekend World Interview.
"The prime minister will make her most effective contribution to the Conservative Party by being what she is and not by trying to be something different. Others then have to provide the balance in that situation."
He was famously branded a "semi-detached member of the Cabinet" by Mrs Thatcher's press secretary Bernard Ingham, following the Weekend World interview and was sacked from Cabinet after the 1987 election.
Biffen retaliated by saying Ingham was the "sewer and not the sewerage" and describing the Thatcher government as a "sort of Stalinist regime".
Years later, he was more philosophical about his sacking.
"I shall go through life as 'semi-detached,'" he told The Times in 2004.
"That halter has been put round my neck by Mr Ingham. Nothing I can do about it.
"I replied that he was the sewer and not the sewage. That wasn't my natural behaviour. I'm really rather quiet.
"Second to being a football manager, being a Cabinet minister is a short-lived experience.
"That's the way of the job. You can't complain about being scratched if you work in a menagerie."
On the backbenches, Biffen voted against the Local Government Finance Act 1988 which introduced the Community Charge, or Poll Tax, and continued to be a staunch defender of the House of Commons.
In 1989, just before the Commons was televised, he asked the then Leader of the House to ensure the character of the Commons was not destroyed.
"It is theatre. It always has been theatre and as long as it has the vitality of trying to represent the wide range of opinions that are argued outside of a saloon bar and are put in a rather different form in this place - it will retain its vitality."
He became a life peer in 1997 and continued to campaign against the growth of EU power, writing in the Guardian in 2005: "I am sorry we shall not have a referendum on the European constitution. I would have voted no with great enthusiasm."
He suffered kidney failure in 2000 and was dogged by health problems for the remainder of his life, finally being admitted to hospital in Shrewsbury at the weekend with septicaemia.
He is survived by his wife Sarah, stepson Nicholas Wood and stepdaughter Lucy Eggleton.