Civil Service staff cuts of up to 40% are being considered as part of plans for the Department for Education, according to Nadhim Zahawi.

The Education Secretary confirmed modelling work to plan for different scenarios is taking place, but insisted he wants to make sure his priorities continue to be delivered.

Unions have criticised Boris Johnson’s plan to cut 90,000 Civil Service jobs, arguing it marks a return to austerity and will damage public services.

The Prime Minister recently tasked his Cabinet with shrinking the size of the service by a fifth, using the savings for tax cuts to ease the cost-of-living crisis.

Mr Zahawi, asked if cuts of up to 40% have been modelled for his department, told Sophy Ridge on Sunday on Sky News: “We are looking at everything.”

Pressed on the figure, Mr Zahawi replied: “We will look at all options, hear me out, as it’s important, these are people’s lives, I’ve got great civil servants who are doing great work in my department on my three priorities.”

These include skills, schools and families, with Mr Zahawi adding: “I need my people to basically be focusing on my priorities.

“The way we shape the department – I’ve got 8,000 people, we’re going to drop to about 7,150 because that’s part of what we’ve done in the spending review settlement, it’s about an 11% to 12% decrease already, but we’ll look at where else we can make savings across Government because, actually, we are servicing a debt today, the debt servicing is £83 billion a year.”

Asked again if the 40% figure is accurate, Mr Zahawi said: “We’re looking to model 10% – we’re above that already – 20%, 30%, 40%, we will model across that. The thing to be aware of is my focus is to deliver outcomes.”