Schools “won’t be sued” if they don’t carry out mass testing slated for January, the schools minister has said.

In a conversation with MPs on Friday, the details of which were leaked to Schools Week, Nick Gibb admitted it was “not ideal” that the government had announced the programme so close to the end of term, but said it was necessary to “break that chain of transmission after Christmas”.

It’s not mandatory, they won’t be sued if they don’t do it

Leaders were first told about the testing, which is supposed to begin in all secondary schools in the first week back in January, on Tuesday, with further details only set out on Thursday, the same day many schools broke up for the holidays.

But the Department for Education has since clarified that participation in the testing will not be mandatory for schools.

Gibb reiterated this to MPs on Friday, telling the government was “asking schools” to take part.

“Again, it’s not mandatory, they won’t be sued if they don’t do it,” he added.

Education secretary Gavin Williamson used powers under emergency coronavirus legislation for the first time this week against Greenwich Council, which had asked schools in the London borough to move to remote learning from Tuesday this week. The council’s direction was in conflict with government guidance to stay open until Thursday at the earliest.

Unions and professional associations said this week that the testing scheme would be “inoperable” for most schools, and said they would back any institution that could not implement it.

The department would not confirm when asked by Schools Week if it would look at taking action against schools that refuse to roll out testing.

But Gibb told MPs schools that struggled would be supported, not prosecuted.

“People don’t need to worry that they’ll be in trouble if they have insurmountable difficulties with doing it. Our regional teams will offer support and there will be support for all schools doing this.

But during his briefing of MPs, Gibb was warned there would now be an “expectation” that schools will have the testing up and running in January, leading to leaders getting a “hammering” from their parents.

The minister said he was under “no illusion about the criticism of the fact we weren’t able to announce this until Thursday”.

“I wish we could have announced this before the day before the end of term, absolutely, but you know, we are where we are and we have to do what we have to do in terms of a pandemic. I want to make sure that we get this thing announced and if we take criticism for that I’ll just have to take that.

However, Gibb said the additional provision of 11 million tests to allow 5.5 million secondary school pupils to be tested twice once they return to school, on top of routine testing for staff and repeated tests for contacts of confirmed cases, was a “good news story”.

“I am aware about the pressure we’re putting schools under, but this is a very big crisis for our country and we have to make sure we break that chain of transmission after Christmas and we need to make sure we’re keeping our schools safe.”