you do not need to declare anything and no trouble.

A friend of mine transfered £200,000 from China to buy a house, no trouble.

Do tell anybody in this country about it, just in case somebody grass you up to Inland Revenue. It is not likely they would go to China to do a seedy investigation, you just do need the trouble.

Anybody asks, tell him/her it is not his/her business; if the estate agency or the bank ask, tell them the money is gift from your parents.