Should you be a Good Samaritan – or walk by?

Boris Johnson, London's Mayor, says the streets are now so dangerous that he has told his children never to intervene in trouble. Is he right?

Jo Brand: 'It depends where you are and the time of the week'

You have to be very sensible when you are confronted with these things especially if there appear to be weapons about. So I would probably say don't get involved. That said I did once see a woman getting beaten up by a man in Camden Market and I just couldn't resist getting involved. He was so shocked that I said anything that he stopped and this gave the woman the moment she needed and she hit him on the head with an umbrella. So in that case there was a good outcome. But if people don't get stuck in that allows bullies to get away with it. I am not sure things are worse than they were 20 or 30 years ago. It depends where you are and what time of the week it is – Friday and Saturday night in the city centre are obviously worse. You have to approach these things very sensibly.

Jo Brand is a comedian

Henry Bonsu: 'If there are enough of you it is an obligation to help'

When I was young, I was interventionist by nature. I'd always step in, but of course, in those days we were not having to deal with guns. Last year I intervened when a group of girls were fighting at Shepherd's Bush. I could have walked on by, but I thought one of the girls might get seriously hurt. So, I said to one guy: "Look, are we going to step in?" If I was alone, I might not have done it. Because, if just one person gets involved, it might be dangerous, but if there are more, the whole thing can be quickly resolved. I've travelled to Ghana, and there, whenever there's a woman in trouble, several people step in and break it up, and sometimes beat the aggressor too. If there are no adults around, and there are enough kids around, they need to step in too, because it can be a difference between life and death. If there are enough of them, it is a moral obligation to do something.

Henry Bonsu is a director and presenter of Colourful Radio

Ann Widdecombe: 'Everyone has to make their own judgement'

It is a great pity that we have lost our have-a-go attitude. One of the reasons we have lost it is not because of fear of the criminal but fear of the police. There have been numerous occasions where people have intervened and then found themselves on the wrong side of the law. I have never had to do it myself. If you see someone flashing a knife I am sure that the preservation instinct kicks in, if there is an affray and you have a bit more time you may call the police. Most people will reach for their phone from a safe distance. I made a television programme about girl gangs and one of the girls told me how she was on the ground having her head kicked. It was only because a lady intervened that they stopped. If the lady hadn't she might have died. Everyone has to make their own judgement.

Ann Widdecombe is an MP, broadcaster and former Home Office minister

Brian Paddick: 'Call the police. That's the responsible thing to do'

If we're going to make progress, then everyone has to take responsibility without having to take risks. To be fair to Boris, what he said was not that people should just walk on by. What he said was that teenagers should not get involved in fights. That's different to saying that you should just ignore things. I think what he was saying was that you should take the appropriate action depending on the circumstances, which is absolutely right. You need to make the correct judgements, and as adults we should be able to do that. As far as teenagers go, I would say if you see a fight dial 999 – call the police. That's the most responsible thing to do. I would not advise any young person to have a go in the sense of jumping into a fight, because it's far too dangerous. With so many teenagers carrying knives it's not safe to get involved, because you don't know if they have a knife or not, and in many cases often they will. Just call the police.

Brian Paddick is a former deputy assistant commissioner of the Metropolitan Police

Erik Baskind: 'If you have to react, then be rapid, sharp and hard'

The official advice is this: if you have the chance, then simply walk on by, make yourself safe and call for police assistance. The only exception to that is either when you are involved and cannot get away or you feel you have a duty to intervene and you feel competent and confident to do so. There is obviously a risk involved in this and that is where training comes in. You need to immobilise the attacker for the few vital seconds it takes to get away. There are a whole range of things to do. It could be a very rapid but serious kick in the shins or grabbing a male in the testicles. Whatever you do it has to be rapid and sharp and hard. If you are not going to do it properly – don't do it. The situation doesn't change when you are confronted with more than one person. Follow the same rules. Ideally you should learn to avoid situations in the first place. The key is always to get away as quickly as possible.

Erik Baskind is director of training at the British Self Defence Governing Body

John Nicho: 'If my mum was in trouble I'd want someone to help'

I am not sure what I would do now. Two incidents stick in the mind. The first was when myself and an RAF boxing champion friend went to help a young policewoman in Oxford who tried to stop three guys jumping off a bridge into the river. They turned on her and we intervened but for five minutes until the police came we were pretty much on our own. Another time I helped out a security guard who was grappling with this young kid with a knife. Basically I'm a coward. I was in the RAF but I'm not trained for these things. I don't look for trouble but I always think, "What would I want other people to do if it was my mum or my wife that was in trouble?" I would want someone to go to their aid. The danger is, will you end up with a knife between the shoulder blades? I hope I would have the courage now but you have to be careful.

John Nichol is a former RAF navigator who was captured during the first Gulf War