The PR referendum held in 2011 was beaten 2:1
The Tories paid lip service to Clegg's crew to hold the referendum and helped make it a forgone conclusion that it would lose.
Could be the Starmer believes it's better/fairer but doesn't help to win the next GE.
Number 1 priority is to kick Thick Lizzy (if she's still there) and the rest out as soon as possible by as big a majority as possible.
There will be enough to do in the first term to stop the shitshow and start recovery, then get a second term to make things better all round.