One Tory insider this morning branded the move a "gift", chuckling over the fact that Starmer might have just lost himself both upcoming by-elections.
Jacob Rees-Mogg claimed on GB News that it is the equivalent of conducting a second referendum "by stealth".
And James Cleverly outright described it as "delusional".
One thing is for sure: by reopening the debate, Starmer has mystified almost everyone.
Brexiteers just want to get on with living outside of the EU, making the most of the UK's independence. EU leaders are bored of the back and forth with the UK. And most Remainers seem to have stopped their campaign to bring the UK back into the EU. There was finally a little bit of peace.
So who has the Labour leader actually pleased with this policy announcement? Right now the most accurate answer seems to be, well, Tory MPs.
The Conservative Party had finally began to ease off on branding Starmer a "Rejoiner" - but now the Leader of the Opposition has started to discuss carving out a new relationship with the EU, they've been given some fresh ammunition.
There is genuine confusion among Tory ranks about why the Labour leader has jumped in so early to announce controversial policies ahead of two critical by-elections taking place next month.
By-elections won't be won on major policy announcements like this, as they wouldn't kick in until after the general election next year. But they might well be lost on it if eurosceptic voters get spooked by such a seemingly pro-European stance.