I object to it for a number of reasons, but the main one is there isn't a hope in hell of it being administered in a fair way.
If one house on a street breaks through the £2m ceiling, do all the other houses on the street suddenly become liable? Who decides what is a £2.2m house and a £1.95m house without selling them all? Estate agents can only judge sale prices within 10% on a good day, and given how common it is now for houses in London to go to sealed bids way over the asking price, they are often out by more than that.
Secondly, it is deeply, deeply unfair to people who have seen their houses rise in the 20+ years since they've been there, while their salaries haven't.
There are ex-council places in nicer parts of London which are now worth over a million. If prices keep rising at a similar pace over the next 10 years, something worth £1m today will be worth £2m in 8 years. The people living there will still be council tenants who bought years ago.
Thirdly, anyone who thinks this won't spread to all houses over the course of a few parliaments is utterly deluded. The next budget after its introduction will see it being extended to £1m+, then £500k and then £250k in line with stamp duty.
It all very well maintaining the 'fuck London, they deserve it' attitude, but there are only so many cheaper Northern towns everyone can sell up and move to before the whole country is paying it