This petition was rejected

The Government e-Petitions Team gave the following reason:

We understand you're concerned about the sentences imposed on those convicted of murder using a knife. However the law does not set out different sentences for murder depending on the weapon used, so it's not clear how this would work.

Further, the law already requires judges to impose life sentences in murder cases. You can find out more about this here: www.cps.gov.uk/legal-guidance/sentencing-mandatory-life-sentences-murder-cases. However, it is for the courts to determine the most appropriate 'minimum term' which must be served before the offender is eligible for parole.

You could therefore have a petition calling on the Government to bring in mandatory whole life terms for those convicted of murder, with no possibility of parole, if that is something you'd like to see happen.