Ken Clarke, the Justice Secretary, yesterday opened a fresh rift with the Home Secretary, Theresa May, over whether to jail children found guilty of knife crime.
Plans for automatic prison sentences of six months for knife-wielding adults are currently going through Parliament, but Mrs May has signalled she wants the punishment extended to under-18s.
Boris Johnson, the Mayor of London, and Conservative MPs, have argued that the planned age for an automatic custodial sentence for using a knife to threaten life should be lowered. But appearing before MPs, Mr Clarke made clear he opposed the move, warning it would run counter to Britain's criminal justice system.
The Cabinet colleagues clashed at the Tory conference when Mr Clarke ridiculed Mrs May's claims that an illegal immigrant had avoided deportation under human rights legislation because of his pet cat.
Mr Clarke told the Home Affairs Select Committee that he supported automatic jail terms for knife-carrying adults, but added: "The idea that mandatory sentences now apply to certain types of offence, to young offenders, to children, to juveniles, is a bit of a leap for the judicial system."