[Cronos]

well, the thing is, without the monarchy, the UK ends -- though you can say that Scotland is already going its own way, but then the welsh and possibly northern Irish will leave

And the Isle of Man and the Channel Islands are in personal union with the crown, so they would become independent.

Normally a long-drawn out monarchy doesn't leave, unless it is evicted in a revolution -- as in the French monarchy (800 years) or the Russian (400).

the british monarchy nearly bought it in the 1600s, but it survived.

There's no reason a Republican government would do better in England.

[Republican Wildcat]

There is the also the issue of what essentially is a binding treaty with the other Commonwealth Realms that are fully independent and have their own monarchy as an institution, but using the same Royal Family to reign (example - Queen Elizabeth II is fully and independently the Queen of Canada or Queen of Jamaica) - all of them would have to agree to the changes I would think.