That's not correct, crown consent cannot stop a vote. And regardless of this, parliament is sovereign [0], that supremacy overrides any power any monarch could have in the UK.
[0]: https://en.wikipedia.org/wiki/Parliamentary_sovereignty
[0]: https://en.wikipedia.org/wiki/Parliamentary_sovereignty
That said, it would be very interesting if such a veto was attempted and it went to court, we’d get to see more constitutional clarification in action!