Is it OK for a non-elected official, however important he may be, to challenge the position taken up by a legitimate political party?
Even if you consider that the Conservative Party is - in this case - barking up the wrong tree, as well as behaving in a disgracefully opportunistic manner, and even if you agree with the sentiments expressed by Mr Starmer, there is something not right about his outburst. Who elected him to take up a position on a matter of political controversy? And, the next time a non-elected official sticks his oar in, it may not be in pursuance of right-on, liberal-thinking policies.
So perhaps, like a good cobbler, Mr Starmer should stick to his last and leave the politics to those elected for that purpose.