Two prominent multi-academy trusts are breaking ranks on the government’s plan for a wider reopening of schools from 1 June.

The Elliot Foundation and Dixons Academies Trust, which have a combined total of 40 primary, infant and all-through schools, say they will not be opening to more children until 8 June at the earliest - a week after the government’s current reopening target.

Hugh Greenway, chief executive of the Elliot Foundation, also said he would be “surprised” if the education secretary was able to prove the government had met its five key tests by 28 May, when it is due to make a final decision on whether to reopen schools from 1 June.

Background: MATs warn of ‘irreparable’ damage if schools don’t open

Coronavirus: Fresh defiance over schools reopening on 1 June

Related: Increasing signs of rebellion over school opening plan

The news comes just days after both trusts signed a letter to The Times, together with 20 other MATs, backing the government’s plans to reopen schools to Reception, Year 1 and Year 6 pupils from 1 June.

The letter warned that the impact of lost learning during the coronavirus crisis could be “calamitous” and “irreparable” if schools remained closed.

Mr Greenway said his trust would not be opening its 28 primary and infant schools before 8 June, as there is “insufficient time remaining to scrutinise the plans and risks in enough detail”.

Dixons Academies Trust, which runs five primary and all-through schools, as well as several secondary and sixth-form academies, has also said it will initially open to more pupils in Year 1 from 8 June, and will extend provision to those in nursery, Reception and Year 6 “at some point” from 15 June.

Mr Greenway said he had signed the letter calling for schools to reopen soon because he supported its “core message”, which he said was “a call to improve the quality of debate around the issue and to work together as a sector”.

However, he said that the MAT has today decided to delay its reopening date until 8 June at the earliest, as “our first priority remains the safety of our children and staff”.

Mr Greenway said “the date itself is irrelevant”, and stressed that the key issue at play is “the thoroughness of the process to mitigate the unavoidable risks”. 

“I would be surprised if the secretary of state is able to say he’s met his five tests as early as 28 May,” he said.

“The thing that is important about the secretary of state’s announcement is that he releases it together with the data that underpins it, because that’s the thing that matters.

“We’ve got to build confidence in society as a whole, and what we can’t have is just an assertion that tests have [been] met.

“What we can’t have is people in authority making assertions that it is absolutely safe - or it’s just as bad to say I can give you no guarantees. Because that’s rude.”

In a letter sent to families yesterday, Sir Nick Weller, chief executive officer of Dixons Academies Trust, said the trust is taking a “deliberately cautious approach” to reopening to more pupils, and will scale up provision “only when we have reassured ourselves that we are ready to do so”.

He explains the trust plans to bring more pupils in Year 1 back to school from 8 June, and will expand this offer to those in nursery, Reception and Year 6 from 15 June.

The letter states: “From Monday 1 June, we shall be finalising arrangements on each site and training staff in small groups on the new routines and systems to keep everyone safe.

“While we recognise that social distancing with very young children is impossible throughout the day, we shall be organising staff and children into smaller ‘bubbles’ to ensure there is no direct contact with anyone outside of their class of 15 and two staff members.

“They will have a single dedicated classroom and designated toilet and washing facilities.

“The choice is yours as to whether you choose to send your child back to school and we will respect your decision either way, but I hope that you will give it serious consideration.”

The Department for Education (DfE) said it would encourage all settings to plan for reopening to more pupils from 1 June, in line with the current government guidance.

A DfE spokesperson said: “We want children back in schools as soon as possible because being with their teachers and friends is so important for their education and their wellbeing.

“Plans for a cautious, phased return of some year groups from 1 June, at the earliest, are based on the best scientific and medical advice. The welfare of children and staff has been at the heart of all decision making.

“We have engaged closely with a range of relevant organisations, including the unions, throughout the past eight weeks, including organising for them to hear directly from the government’s scientific advisers last Friday, and will continue to do so.

“We have also published detailed guidance on the protective measures schools should take to reduce the risk of transmission.”