I understand the sentiment but the way that they are going about this is just going to blow up in their face and make them look bad.
If they had just quietly changed the sentencing laws to say “A sentence of 25 years imprisonment issued against a defendant convicted of culpable homicide is interpreted to mean a sentence of life imprisonment with a minimum tariff of 25 years”, nobody would have batted an eye.
It makes prison sentences more arbitrary rather than there being a standard fixed in law that is applied universally, somewhat objectively, and not subject to a single person’s unchecked discretion.
As with anything that allows for state power to be exercised more arbitrarily, this legislation is autocratising. That’s not necessarily a bad thing—it just means you have to put more trust in the Government to not abuse the power they’ve gained.