A landmark Supreme Court ruling has put the ‘best interests of the child’ at the centre of decision-making in immigration cases involving the deportation or removal of their parents.

Giving judgment last week in the case of ZH, a Tanzanian woman who had made three failed asylum claims, Lady Hale said the best interests of the former’s British-born children, now aged 12 and nine, must be a ‘primary consideration’.

She said the children were British, not just through the ‘accident’ of being born here, but because they had a British father, had lived all their lives here and were educated here. ‘It is not enough to say that a young child may readily adapt to life in another country,’ she said.

Hale said: ‘The intrinsic importance of citizenship cannot be played down. As citizens, these children have rights which they will not be able to exercise if they move to another country.’

Lord Kerr said that ‘only reasons of considerable force’ could displace the primacy of the best interests consideration.

Syd Bolton, co-director of the Refugee Children’s Rights Project, run by the Children’s Legal Centre and the Islington Law Centre, said the decision marked a ‘significant step forward’ and highlighted the vulnerability of children in the immigration system.

He called on the courts, the UK Border Agency and the Legal Services Commission to put in place child-sensitive procedures to ensure they give full effect to the judgment in their duties to safeguard children.

He added: ‘The government’s proposals to cut legal aid funding would deny access to justice for these children. If these proposals come to fruition an important case such as this may never reach the court’s doors.’

Alison Harvey, general secretary of the Immigration Law Practitioners Association, said that while the case did not mean a child’s interest cannot be outweighed by other matters, or that a parent’s immigration history will be irrelevant, it does mean that decision-makers must be careful to avoid treating children as responsible for their parents’ actions.

Harvey welcomed the emphasis the court put on the importance of ensuring that children are given a proper opportunity to have their views heard.