As I remember, when UK referenda were merely mooted, it was said that they made France ungovernable. Not quite here (yet) but the pattern is remarkably reminiscent.
Maybe PM TM is banking on getting in quick, before JC can be shown to be Michael Foot Mk2 and TM knows we are heading for serious heartache over trade, and she needs 5 more years to prove herself & the economy.

Time will tell, let us hope it doesn't shout!