Are there any restrictions on immigrants from party member in Britain?

No, according to Article 17 of the Implementation Rules of the Exit and Entry Administration Law of People's Republic of China (PRC), party member can immigrate to non-immigrant visa types, such as studying abroad, visiting relatives, doing business, traveling, etc. If the visa applicant has reasonable reasons for going abroad, and can convince the visa officer of these reasons, the visa officer will not take party member status as the reason for refusing the visa. If he meets the requirements, he will not be deported because of his party member status. So Britain has no restrictions on party member immigrants.