Look Who's Talking: Thatcher always made me suffer: Jon Snow on being thrown out of university, his tie collection, and the problems of behaving too well on air

Jon Snow presents Channel 4 News on weekdays at 7pm. He is currently also presenting 'Class Action' on Channel 4, on Fridays at 8pm.

MARGARET THATCHER was always a tough cookie to interview because there was so much in play. More important than anything, I was a man and she was a woman and that definitely interfered in the process - I'm not saying that it was raw sex but there was something about her use of her sexuality which put you at a considerable disadvantage. There was the 'How dare you ask a question like that?' response which if a man used you'd say 'I'll ask any bloody question I want.'

I always came away from interviews feeling she'd got the upper hand. She liked being interviewed by people who were antagonistic because she liked nothing better than to be wound up and to fly. It would be great television but you'd be the victim.

John Major is an extremely efficient, well-briefed interviewee. He disguises the ruthless politician that he actually must be; nobody could survive what he's been through if he wasn't. But on the surface he appears to be a very engaging, charming man. Again, I come away feeling I haven't done what I should have done, which was to leave him lying all over the floor. I rarely finish an interview thinking I've been too hard on people; often I regret not having been harder. It's a self-censoring medium and you behave much better on air than you would off.

I joined ITN 18 years ago and I was a diplomatic correspondent until I started presenting Channel 4 News five years ago. I got the job suddenly because Peter Sissons left; literally, that night I had to go on as there wasn't anybody else.

The colourful ties came about when somebody said to me, 'You'll have to have a trade mark because you're essentially a boring-looking fellow.' Robin Day had his bow-tie, Reggie (Bosanquet) had his toupee (although you could never mention it) and I realised that ties were the answer. At first some tried to stop me wearing them, saying they interfered with concentration and were inappropriate. Today I have about 50.

There are lessons you learn doing the job. I'm very conscious of the need to sit up and there's a make-up artist who rushes in during the break to tidy me up if I sweat. You do break into a sweat in an embarrassing or difficult situation.

I went to university in Liverpool in the late Sixties and was expelled for 'political activity' centring on the university's investments in South Africa. The chancellor, the then Lord Salisbury, had a less than embracing attitude towards the majority in South Africa and 10 of us were rusticated, as they put it. It was the end of my education.

If I'd been allowed to finish my degree I'd have become a rather inept and inefficient barrister, so on the one hand it's the best thing that's ever happened to me; on the other, I feel aggrieved because I was denied natural justice and had a perfectly coherent case which I was never allowed to put.

I have two daughters, aged eight and 11, but I'm not as involved in their education as much as I'd like to be. I look after them in the morning and take them to school but they're in bed by the time I get home, though still awake and ready to be read to.

I live in Kentish Town and cycle the 15 minutes to work for the planning meeting at 9.30. If you miss that you never really catch up, but as long as I'm in for it I know I can put in my pound of flesh and help shape the programme.

I don't think anybody could do a proper job in news and current affairs if they weren't politically driven. But I'd never enter politics as an MP - I couldn't take the salary cut.

(Photograph omitted)