Straw's not tough enough for the playground jury

You know something's wrong, because you get told off by your mum. Stealing is all right if you are starving because otherwise you might die, but you shouldn't mug someone even if you're hungry because they might have to go to hospital. Grassing on your friends is always wrong, but not if they have done a murder. Then you should tell the police, but be careful because otherwise they might kill you for grassing.

This is the law according to five inner-city 10-year-olds.

Under proposals outlined in the Queen's Speech last week, 10-to -14-year- olds are for the first time to be deemed capable in law of telling right from wrong. As the law stands, children of these ages can only be convicted of crimes if the prosecution can prove they have "mischievous discretion". The Crime and Disorder Bill proposed by Jack Straw, the Home Secretary, will scrap the assumption that they do not.

Jack, Sam, Enrico, Jamie and Siobhan agree with Mr Straw that at 10 they know right from wrong. "Nine-year-olds wouldn't know the difference," says Sam earnestly, scuffing his Nike trainers, "but at 10 you're grown up."

To these five children at the Arches after-schools club, a stone's throw from the old Labour Party HQ on Walworth Road in south London, 10 is old and 14 ancient.

The five make a list of all the things that are definitely wrong: stealing, rape, robbery, taking drugs, murder and hurting people with a baseball bat. Hitting someone is wrong unless they are hitting your friend and then you have to hit them. Breaking up fights is wrong because it is not your business. Racism is wrong and you should go to prison for it.

"With lying, it depends on whether it's adults or children lying,"says Jack, an Arsenal fan.

All five children go to church sometimes and say they believe in God, but they don't see what that has to do with right and wrong. You know something's wrong if your mum or a teacher tells you. Then you remember it the next time.

The Catholic church recognises seven as the "age of reason" in a law which pre-dates the Council of Trent of 1562. Prior to that age, children cannot sin. In medieval philosophy, children were incapable of performing "fully human acts" and were not held to be "morally responsible" prior to the age of seven.

In secular law, the minimum age of criminal responsibility - also known as the age of criminality - was set at 14 by Sir Edward Coke in the 17th century. Children below that age and above the age of seven could be convicted of crimes, but only if the prosecution could demonstrate "mischievous discretion".

In 1933, the Children and Young Persons Act raised the minimum age for prosecution from seven to eight, and in 1963 it was raised to 10. Today, a child under 10 is still regarded as being "doli incapax" or "incapable of committing serious wrong". In cases where children are aged between 10 and 14, it is assumed that they don't know the difference between right and wrong unless the prosecution can show otherwise.

Labour's proposal to place the burden of proof on the defence reflects national concern about the incidence of serious juvenile crime.

Since 11-year-old Mary Bell was convicted of the manslaughter of two boys in 1968, children between the ages of 10 and 14 have been found guilty of serious crimes. In 1995 Robert Thompson and Jon Venables, both 10, were jailed for the murder of two-year-old James Bulger. Last June, a 14-year-old boy was given a 20-year sentence for a hammer attack on a woman who made sexual advances towards him and an 11-year-old boy was convicted of killing a pensioner by dropping a concrete slab from the 12th floor of a building.

Last May, two schoolgirls, one 11, the other 12, were found guilty of the manslaughter of 12-year-old Louise Allen, after kicking her to death.

The package unveiled last week in the Commons includes other measures aimed at "zero tolerance", including children as young as 10 working in the community as punishment for crimes, curfews for some under 10s and replacing repeated police cautions with a single final warning.

Enrico adds breaking into cars to the list of things which are wrong. "I know it's wrong because I got caught and the police came and my brother and my cousin ran off and I had to go to the police station and go in a cell," he says in a rush. He didn't tell on his twin brother, Sam, because "you don't grass".

Sam's and Enrico's dad is in prison. "He's been in four times for robbery," say Sam. "When he gets out he'll do it again and probably go back again." Sam says prison is horrible. "It's full of old men and if you get sent there they take all your clothes and everything in your pockets and then they spray you with a hose," he explains. "When we went to see my dad, we had to go through a thing that can see metal in case you have a gun or a knife, and Enrico's belt was made of metal so he got into trouble."

Jamie says that going to prison makes you worse because you have to live with criminals. "And there's drugs in prisons. You hide them under your tongue, like this," he says, blowing out his cheeks. Jon and Siobhan say this idea is ridiculous, because the police would see and make you spit it out.

The children are even harder on 10-year-olds than Mr Straw. "If you do wrong," says Sam, "you should pay for it." Siobhan says children should go to prison, but a different one from adults. Enrico says he won't steal again because then he won't be able to be a fireman when he grows up.

Jamie says that if you break the law you're not allowed to be famous. The others nod wisely, but Sam suddenly blurts out: "What about Mark Morrison [the soul singer recently jailed for a stun gun incident]? He went to prison and he's still famous!"

Still pondering this confusing aspect of British law, the impromptu panel on juvenile justice goes back to kicking a ball around outside the play centre.