A review of the murder laws is to begin next year, the Home Office has said.
The Law Commission suggested murders could be 'graded'
It comes in the wake of a Law Commission report in August branding the current murder law "a mess".
A Home Office press release said the legislation had to be "clear, comprehensive and fair" to "ensure public confidence".
Home Secretary David Blunkett was due to announce the move during a Commons debate on the Domestic Violence, Crime and Victims Bill on Wednesday.
Mr Blunkett later admitted through a spokesman that the press release had been issued too early.
But he also blamed a Conservative "filibuster" for preventing him from making the announcement to the House.
The spokesman said it was up to the Speaker to decide whether the home secretary should still make a Commons statement on the issue.
Earlier on Wednesday, a Home Office spokeswoman said the terms of reference for the review had not been established, but it was likely to just include England and Wales.
In its report, the Law Commission said it had found wide support among criminal justice professionals for an end to the mandatory life sentence for murder.
The panel suggested different kinds of murders could be "graded" to recognise the seriousness of the offence.
But the Home Office said then mandatory life sentences would not be abolished and argued courts already had flexibility.
The commission, an independent body including two judges, a senior barrister and sentencing experts, had been asked to consider reforms to the defence of provocation in murder cases.
But it said its proposals were unlikely to work without a far wider review of the law.
Results of a consultation exercise showed 64 respondents out of 146 - among them 21 judges - believed a mandatory life sentence for every murder was "indefensible and should cease".
A key question was whether one category should continue to cover all types of murder from mercy killings to serial or contract killings.
The commission found support for the idea of grading murders, so that the sentence reflected the seriousness of the offence.
But speaking after the report was published, Home Office minister Baroness Scotland said: "Murder is the most serious of crimes and we have no intention of abolishing the mandatory life sentence.
"Where an offender is convicted of murder, the court must pass a life sentence."
The commission also recommended tightening the law so that the provocation defence cannot be used in cases where someone has killed for revenge, for example a jealous husband who murders an unfaithful wife.