I'm not entirely certain of the electoral details, but the UK Labour party is neck-and-neck with the UK Conservatives for falling from being a top-2 party [0]. This type of decisive reform may be sufficient to keep them out of 3rd place, so it is worth a try. The voters could take to it.

[0] https://en.wikipedia.org/wiki/Opinion_polling_for_the_next_U...

The collapse of the ancient Conservative party to behind not one but two crank astroturf right-wing parties is something to behold.