Britain is to give £90m to help children in conflict zones go to school, Boris Johnson has announced.

Announcing the aid boost at the G7 summit in France, the prime minister said it would help an estimated 600,000 children, particularly girls, in some of the world’s most dangerous and unstable countries.

He called on other rich-world countries to devote a greater proportion of their aid budget to education, which currently accounts for less than 2 per cent of global humanitarian assistance.

One in four of children who do not attend school live in countries affected by conflict, humanitarian emergencies and prolonged crises, with girls making up the vast majority of them.

Girls are more than twice as likely to be out of education and almost 90 per cent more likely to miss secondary school if they live in conflict zones. Families are more likely to keep girls home than boys if there is a risk of sexual or other violence at or on the way to school.

African refugees study at a school backed by UK aid money (UKaid/Department for International Development) (UKAid/DfID)

Mr Johnson made education for girls a priority of his time as foreign secretary, when he signed the UK up to a safe schools declaration, committing to the protection of educational institutions during military operations.

With tackling inequality a key theme of the G7 summit of world powers in Biarritz, he will tell fellow leaders that it cannot be achieved without a global commitment to girls’ education.

The UK aid money will support the work of the global fund for education in emergencies, Education Cannot Wait, which the UK helped to set up in 2016.

Mr Johnson said that the “cycle of instability” in some developing countries could only be broken by equipping the adults of tomorrow with learning and skills.

“It is girls that suffer most growing up in societies marred by violence. We owe them better,” he said.

“Girls’ education is the Swiss Army knife that solves a multitude of the world’s problems. Everyone benefits from a world where girls have the same opportunities as their brothers.

“I pledged on the steps of Downing Street to ensure that every girl in the world gets 12 years of quality education. I’m proud that today’s announcement will help us do that.”