Mental health treatment would be available within a month for all who need it under a Labour government, Sir Keir Starmer is to announce.

The Labour leader will say that 8,500 new staff would help one million extra people access mental health treatment – not purely an initial assessment – which Sir Keir will say is “one of the most urgent needs of our time”.

The goal would come in the form of a new NHS target, with mental health hubs for children and young people in every community and specialist mental health support in every school.

While the policy would cost £1.016 billion – by what would theoretically be the last year of Labour’s first term in office in 2028-29, if they were to win the next election – the party said it would be funded by closing tax loopholes and removing the VAT exemption from private schools.

Sir Keir will say: “One of the urgent needs of our time is mental health.

“Labour will guarantee that support will be available in less than a month and offer treatment to a million more people each year who need it.

“We’ll make sure children and young people get early help, putting specialist support in every school and a mental health hub in every community.

“This is prevention in action. Helping young people, looking after their well-being.”