The Education Secretary said he is “absolutely confident” there will be no further delays to school reopenings, after soaring coronavirus case rates in December forced the Government into a U-turn in pushing back the start of terms for millions of pupils.

Gavin Williamson moved to reassure teaching staff, pupils and parents the newly rescheduled staggered return dates for England would remain in place, despite concerns about safety and transmission rates among younger people.

On Wednesday, the Government announced primary school pupils in some of the areas hardest hit by Covid-19 will not return to their desks as planned next week, with students in exam years returning to secondary schools a week later than planned, from January 11, while other secondary and college students will go back full-time on January 18.

The vast majority of primary schools will return on January 4 as planned.

The announcement, less than a week before the start of the new term, was described as a “last-minute mess” by teachers, who accused the Government of failing to heed warnings from school leaders that remote learning may need to be implemented.

But Mr Williamson said he did not anticipate further delays.

The Education Secretary said: “We are absolutely confident that all schools are returning.

“You’re going to see over 85% of primary schools returning on Monday morning, you’re going to be seeing exam cohorts going back right across the country on January 11.”

Asked if he can guarantee that, Mr Williamson said: “We are absolutely confident that is what is going to happen.”

Mr Williamson said his confidence also extended to schools’ readiness to safely accept pupils back into the classroom by executing a mass testing programme on site.

This comes in spite of concerns from teachers about how testing will be conducted safely, and by whom.

Mr Williamson added: “There’s absolutely no reason that schools won’t be ready.”

He said £78 million of additional funding, equipment such as personal protective equipment (PPE) and support from the military would help them get mass testing programmes set up.

Mr Williamson said: “We really want to hold their hands, support them, help them. We’re asking everyone right across the country to do pretty extraordinary things at the moment.”

Drawing on his two school-age daughters’ experience during the pandemic, Mr Williamson said: “How much they (children) miss out by not being in schools, that’s why we’re taking these extraordinary actions because it’s always best to have children in school if it’s possible to do so.”

Geoff Barton, general secretary of the Association of School and College Leaders, accused the Government of living “in a parallel universe”.

He said: “It is asking them to recruit and train large numbers of staff, and set up testing centres in an incredibly short timeframe.

“The support it has announced is nowhere near being sufficient.

“Ministers need to remember that schools and colleges are educational institutions, not medical facilities, and it has to support this testing programme properly.”