The actor Jeremy Irons, 60, has appeared in films ranging from Dead Ringers to Lolita.  His most famous roles include Charles Ryder in the 1981 TV adaptation of Brideshead Revisited and Claus Von Bülow in Reversal of Fortune (1990), for which he won an Oscar.  He is a patron of the Prison Phoenix Trust, which teaches yoga and meditation to prisoners in British and Irish jails (www.prisonphoenixtrust.org).

Which cause do you feel most passionately about?

Probably the Prison Phoenix Trust.  Without injecting a huge amount of money, it helps those inside vent their anger, and to build a habit to support them both in prison and when they get out.

Why should we help prisoners?

Most are people who've been knocked on the head constantly by life: bad parenting, bad schooling . . . Life's clobbered them and they've gone inside. We need to stop the circle of people getting inside, getting out, being unemployed, having bad relationships, having children who are brought up in this atmosphere, who then go inside themselves.  Yoga helps people to develop self- worth, to calm themselves, and to learn to hold down a position in society.

How do you ensure that your donations are used effectively?  As far as I can, I read the accounts and newsletters.   There is a very direct flow of funds with the Phoenix Trust.  I worry about giving to larger charities because of the infrastructure in the countries they work in, where money can get hived off.

What do you get out of your giving?

I'm one of the most fortunate people in the country really, but I believe that it's essential to try to attain balance in every element of life.  By giving a percentage away, there's a feeling that I am, in some way, adjusting the balance.  Also we're all taxed fairly heavily.  We have no choice where that money goes, and it's nice to feel you've made a choice when you give money to an organisation.

Do you make impulse donations?

I do give money to people on the street, not to make them go away, nor because I think they'll spend it wisely, but to make them feel that they are surrounded by compassionate people.

Are prisons useful?

I don't think our prisons are, no.  We've gone badly wrong with our education system.  Single parenting is now acceptable, although we know it's not as efficient for bringing up children as two parents.  We've lost any power to discipline difficult children, so it has become hard to explain that you can be an individual but, to make society work, we have to follow certain rules.  As a result, we've lost the interwar society of good morals, standards and manners.

Prison is the sharp end of that shift.  And because we don't put enough money or thought into prisons, people come out pretty much the same as they went in.   Prison life is too soft.  It should be really tough - but also a repairing process.  You should leave understanding the rules to play by, and why those rules are there.

Interview by Angus Watson