Does giving a British divorce by a husband, who has no intention to break up, nullify the Nikah when the sole reason for giving it is to bring a second wife to the UK, which is otherwise not allowed by UK law unless a divorce is given to the first wife?
Bismihi ta'ala
No, a civil divorce does not take the place of a shar'i divorce.
What this husband must do is find out if his violation of law of the land is sinful and haram.
But nonetheless, it will not affect the shar'i legitimacy of the marriage, and they would still be husband and wife from a shar'i perspective.
And Allah knows best.