Home Secretary David Blunkett has been handed a golden opportunity to close a loophole which lets parents or guardians get away with murder.

The Government has failed to act despite a three-year campaign by The Argus backed by MPs, Sussex Police, Brighton and Hove councillors, the NSPCC and families of murdered children.

The delay is partly down to the lack of a suitable piece of legislation which could be used to drive through the law change.

But MPs said it could now be included in the new Criminal Justice Bill, which was unveiled in yesterday's Queen's Speech.

Mr Blunkett has "not ruled out" putting the change in the first published version of the Bill, which is due out in the next few months.

Even if he fails to do so, the Bill will remain the most likely method of closing the loophole, according to MPs.

Brighton Kemp Town MP Des Turner said he would introduce amendments to include it in the legislation.

Dr Turner said: "I am very anxious to discuss this with David Blunkett.

"I want to persuade him that, if he has not already considered it in the draft versions of the Bill, he should get it in now before the final version is published.

"If it is not I will table amendments but it would be better to do it now rather than at a later stage."

Two Sussex couples suspected of killing children in their care escaped prosecutions for murder in recent years because of the loophole.

A Brighton couple, jailed for cruelty to five children, were originally tried for murdering three babies but the case collapsed in 2000.

Murder charges against Simon and Michelle McWilliam, whose adoptive son John Smith, four, died in their care, failed at the committal stage.

The Portslade couple were jailed for cruelty last year but John's family continues to fight for justice.

The murder charges failed because it could not be proved which of the parties inflicted fatal injuries.

Hove MP Ivor Caplin said: "I spoke to Jack Straw when he was Home Secretary and I know he was very exercised by this issue.

"Knowing David Blunkett, I think he will be exercised by it as well. It is a loophole which needs closing, something which the two Brighton cases have shown."

The Bill, which formed the heart of yesterday's Queen's Speech, aims to rebalance the legal system in favour of the victim.