in the main lobby of the House of Commons and found my own way to the office of the Leader of the Opposition at the far end of the building.
This caused some upset, for security reasons, but the way to Mrs Thatcher's private room is complex. The maze-like corridors arc identical and so are the panelled and green-carpeted rooms which lead off them, though one I accidentally turned into is a rather bleak and utilitarian kitchen.
The inner sanctum is formal but relaxed, and as I went in Mrs Thatcher dressed all in blue, rose from her desk remarking that we would never get through all the questions I had sent her in the time.
"Rather too many than too few," I said, but I needn't have worried, because for the next half hour I didn't get a word in edgeways. 1 had submitted some 24 questions in advance, as she had requested, ranging from her own experience growing up as a Methodist to specific political questions about Northern Ireland, race and immigration, abortion and Third World aid.
Mrs Margaret Thatcher was born and brought up in Grantham. Lincolnshire, where her father, Alfred Roberts, ran a grocer's shop. He was deeply committed in local politics and was much sought after as a lay preacher.
The two girls, Margaret and her elder sister Muriel, had a strict religious upbringing. Sundays meant going to church three times and not being allowed to go to the cinema or play games. They were taught what was right and what was wrong, that cleanliness was next to godliness and the importance of discipline and duty.
I asked her what memories she had of those early years in the Methodist Church.
"Methodism isn't just a religion for Sundays — no faith is only a faith for Sundays. There were a lot of things during the week which one attended. Methodism is a pretty practical faith; there were the mothers' sewing meetings and the guilds for young people.
"It's also evangelical, and does a lot of missionary work overseas. The visiting missionaries, some of them from South America, some from Africa and India, would come back and tell you of the kind of work they were doing.
"I must say I was very much attracted to the work they did because they really could see results."
Although she was married to Denis Thatcher 27 years ago in Wesley's own chapel in the City of London, she has since moved towards Anglicanism and I asked her about this shift.
"You know, John Wesley would of course say that he was a member of the Church of England, and the service he believed in was the Church of England service; but it was too high for the kind of evangelical work he was doing.
"Methodism is the most marvellous evangelical faith and there is the most marvellous love and feeling for music in the Methodist Church which I think is greater than in the Anglican Church. But you sometimes feel the need for a slightly more formal service and perhaps a little bit more formality in the underlying theology too.
"So throughout my life I have felt the need for both things, to some extent for the informality, for the works you do; but always 1 found myself groping out for more of the actual teaching of the religious basis. As I say, I went for something a little more formal. I suppose it's first one's belief and then one's background."
She denies that this move was in any way a rebellion. The need for the formal and the evangelical came to rest for her in the Church of England, "but not the real High Church", she adds.
'What you do has got to be somehow in touch with and in tune with the times.'
1 asked Mrs Thatcher what she thought about the current debate on the ordination of women. She had to think about this one, and made a couple of rather non-committal remarks to start with. It wasn't on the list of questions.
In the end she said: "I don't think that you should stop it, but you have to think very deeply about it. After all, women do so much work; no one ever stopped them being missionaries. I3ut you can't go faster than the adherents of the Church will take; you can't in the Catholic Church either.
"What you do has got to be somehow in touch with and in tune with the times, otherwise you cause friction and you mustn't cause friction if you have a positive message."
1 had asked Mrs Thatcher whether she thought the stress the Conservatives put on independence and individualism really would help those poorest in our society.
She answered this in her explanation of her own beliefs about society. government and religions values which, it seems, grew out of those talks the missionaries gave when she was young.
"If you are faced with the real problems of poverty and ignorance and people don't know how best to grow crops, you've got a pretty simple, straightforward task because you've got to help, and help in practical terms.
"Because while you're teaching them religion you've got to recognise that they are not very likely to receive it or understand it unless it does mean something and enables them to do things for themselves.
"So you replace poverty by a better standard of living out of people's own efforts, because everyone's got talent and ability, and you teach them what we regard as necessary to life, and you teach them religion as well.
'Nowadays there is no primary poverty left in this country.'
"So when you've relieved poverty and ignorance and disease, if you are not a Christian you think that sorts out the problems of the world. You and I know it doesn't, because there is still the real religious problem in the choice between good and evil. Choice is the essence of ethics.
"Nowadays there really is no primary poverty left in this country. In Western countries we are left with the problems which aren't poverty. All right, there may be poverty because people don't know how to budget, don't know how to spend their earnings, but now you are left with the really hard fundamental character — personality defect.
"Why do people turn to drugs? Why do some terrorists come from really good backgrounds in the sense that they were taught the right things and had no shortage of money?
"And here you have the fundamental basis of human nature — there's good and evil in everyone. The fundamental purpose on earth is to impove your own human nature and disposition. You can only do that by doing things for others.
"Even then, when you've been taught all the right things, all the best things, it doesn't mean to say you will do them. "Every person, whether high or low born, whether they get to high places or they have a very simple straightforward life, earning an honest wage for an honest job, each has that human dignity, each has that choice, their responsibility within their knowledge and background to make that choice.
"If you deny that personal responsibility you are denying the religious basis of life — that's the difference between me and a Marxist. The values by which you and I live are not values given by the State.
"Christianity is about more than doing good works. It is a deep faith which expresses itself in your relationship to God. It is a sanctity, and no politician is entitled to take that away from you or to have what I call corporate State activities which only look at interests as a whole.
"So, you've got this double thing which you must aim for in religion, to work to really know your faith and to work it out in everyday life. You can't separate one from the other. Good works are not enough because it would be like trying to cut a flower from its root; the flower would soon die because there would be nothing to revive it."
Mrs Thatcher's defence of the in dividual against the State is in her eyes founded on a Christian concept of man.
"The basis of democracy", she says, "is morality, not majority voting. It is the belief that the majority of people are good and decent and that there are moral standards which come not from the State but from elsewhere."
But how far does this individualism go? I asked her if she thought laws about killing should be simply left to the individual.
"The law is to regulate what you must not do to one another. My freedom must be regulated by your freedom. My freedom to hit out stops at your chin."
As she said this she clenched her fist and smiled delightfully. What about the deviant, I asked, the man who isn't "decent and good"? Shouldn't society behave in a Christian way towards him and forgive him?
"There are two things. First there is reform, then I'm afraid there has to be some retribution for society. there has to be some deterrent, otherwise people would not be able to carry on their life.
"I can well remember listening to a sermon just before Oxford Assizes where the preacher said that certainly retribution is a part of the Christian Faith.
"We have to make secular judgments. It doesn't mean to say that we have to make ultimate judgments. You have to have a strong rule of law, but the moment you get so many laws you're fundamentally denying choice ..."
Next Week: What Mrs Thatcher thinks of abortion and how she exploded at the idea of a Minister for Marriage.