Gavin Williamson is expected to set out new plans for the start of the school term in England in the Commons, amid growing pressure for a delay.
It comes after government health advisers suggested schools may have to close to allow the new, more contagious coronavirus strain to be suppressed.
Health Secretary Matt Hancock told the BBC the new variant meant it was much harder to protect education.
Teaching unions are also calling for a delay so mass testing can be set up.
Speaking on BBC Radio 4's Today Programme, Mr Hancock said: "Clearly we would want to protect education as much as possible, that has been part of our strategy, and throughout autumn I've been really pleased we've managed to protect education all the way through.
"But," he added, "the new variant does make that much easier for this disease to transmit, so we are going to protect education as much as we can, and the education secretary is going to set out his proposals."
The government had proposed a staggered return for secondary pupils in the first two weeks of January, with exam-year pupils and vulnerable pupils returning first. Primary schools were to go back as normal.
The rest had been expected to go back on 11 January.
But details emerged in several media reports on Tuesday of a reported Department for Education plan to delay the start of term by one week for secondary schools, with exam-year pupils (Years 11 and 13) beginning the term online.
The DfE would not confirm these reports, but said the situation was under constant review.
However, it is not yet clear whether these proposals have been agreed by the prime minister.
Mr Williamson may also set out new plans for the start of university terms. Currently, the mass return of students to their university towns is to be staggered, but there are expectations that the migration of a million students may be carried out more slowly.
There have been repeated calls throughout the autumn and winter for teaching to be conducted online instead.
Call for clarity
Geoff Barton, general secretary of the Association of School and College Leaders head teachers' union, said it seemed a "sensible and prudent approach" to delay the return to school, given the rising rates of Covid and the new strain of the virus.
He added: "What is vital is that schools are given clear guidance as soon as possible so they can make the necessary arrangements."
Labour's shadow education secretary Kate Green has been calling for Mr Williamson to come to the House of Commons and set his plans, and for official scientific advice on schools to be published.
She said: "Coronavirus rates are rising, and parents, staff and pupils are crying out for clarity about the start of term next week."
A mass testing programme is being set up and being run by individual secondary schools, backed up remotely by armed forces personnel and public health teams, to try to keep the virus out of schools.
But if term began as previously planned this would entail 5.5 million secondary pupils being tested in schools in the space of a week.
And head teachers said the late announcement of the plan, coming just as schools broke up for Christmas, made it near impossible for schools to deliver.
In response to Tuesday's reports, a spokesman for the Department for Education said: "We want all pupils to return in January as school is the best place for their development and mental health.
"But as the prime minister has said, it is right that we follow the path of the pandemic and keep our approach under constant review."
It added that funds had been made available for schools to hire staff from employment agencies to carry out the testing programme.
Senior Conservative MP Sir Roger Gale also called for a decision to be made "now" on when pupils would return to school.
There have also been repeated calls made for the official advice drawn up by Sage on schools to be made public.
How are the other UK nations returning to school?
- Scotland: Schools will start term on 11 January, with learning taking place online until at least 18 January.
- Wales: Term will start with online learning, but the majority of pupils are expected to resume face-to-face lessons by 11 January. A full return to the classroom is expected to be completed by 18 January.
- Northern Ireland: All schools will initially reopen for face-to-face teaching at the start of term, but years 8 to 10 will move to remote learning from 25 January for at least two weeks.
Schools in all the UK nations are remaining open for vulnerable children. England, Wales and Scotland have also committed to maintain face-to-face teaching for children of key workers.
- FILMS FOR EVERYONE: Check out what films are streaming now on BBC iPlayer
- IDRIS ELBA MEETS PAUL McCARTNEY: Listen to the exclusive interview now...
Do you work in a school? Will you be affected by mass testing in schools? Email email@example.com.
Please include a contact number if you are willing to speak to a BBC journalist. You can also get in touch in the following ways: