In British English, singular words like family, team, government, which refer to groups of people, can be used with either singular or plural verbs and pronouns.
* This team is/are going to lose.
Plural forms are common when the group is considered as a collection of people doing personal things like deciding, hoping or wanting; and in these cases we use who, not which, as a relative pronoun. Singular forms (with which as a relative pronoun) are more common when the group is seen as an impersonal unit. Compare:
* My family have decided to move to Nottingham. They think it's a better place to live.
* The average British family has 3.6 members. It is smaller and richer than 50 years ago.
* The government, who are hoping to ease export restrictions soon, …
* The government, which is elected by a simple majority, …
* My firm are wonderful. They do all they can for me.
* My firm was founded in the 18th century.