[monooso]

It was erected surreptitiously in the dead of night. That does not imply state approval.

As for who paid for it, I don't know, possibly the extremely successful and wealthy artist who created it.

If you have any evidence to the contrary, by all means present it.

[Shocka1]

Anecdote, a close family member of mine is a director of arts for a very large city in the US. They typically install/uninstall at night - she's told me this is especially important with cultural or otherwise edgy pieces.

[gib444]

It not being taken down yet implies state approval (4 days now?). It's on Pall Mall ffs, right near a statue of a King

It's not like the wealthiest city in the UK is lacking in resources to do something about it.