There is a “consequence” to delaying the opening of schools to more pupils, Gavin Williamson told “hero” teachers today.

The education secretary said he understood that teachers were “very anxious” about school reopenings from 1 June.

But he then made the case about why they should go ahead, subject to the government’s five coronavirus safety tests being met.

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“There are some who would like to delay the wider opening of schools but there is a consequence to this,” Mr Williamson said, as he led the daily Downing Street briefing.

“The longer that schools are closed, the more that children miss out. Teachers know this. Teachers know that there are children out there who have not spoken or played with another child their own age for the last two months.

“They know there are children from difficult backgrounds or very unhappy homes for whom school is the happiest moment in their week and it is also the safest place for them to be.”

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He added: “The poorest children, the most disadvantaged children, the children who do not always have the support they need at home, will be the ones who fall furthest behind if we keep school gates closed.”

The education secretary did not directly criticise teaching unions for suggesting the 1 June reopenings should not go ahead.

But he appealed to them to work with the government to find “practical solutions” to enable schools to open.

“My door is always open,” he said. “I am always keen to listen and talk to them. I have been meeting both representative organisations, school groups, but also unions, every single week,” he said.

“I always want to talk. We want to find practical solutions to make sure that those children from that most disadvantaged background don’t lose out as a result of this crisis.

“I hope everyone is unified in that mission to deliver that.”

Mr Williamson also praised the profession, saying: “Teachers have been absolute heroes all the way through this crisis. They have been leading by example… they understand the importance of schooling.”

Patrick Roach, general secretary of the NASUWT teaching union, welcomed Mr Williamson’s commitment to talk, saying it was essential that ministers provided the reassurance teachers were seeking.

“Schools are looking to the government for clear and unequivocal guidance on the health and safety measures they will need to have in place prior to reopening,” he said.

“The bottom line is that no teacher or child should be expected to go into schools until it can be demonstrated that it is safe for them to do so.”

Kevin Courtney, the joint general secretary of the NEU teaching union, welcomed the commitment by Mr Williamson to monitor the effects of this week’s loosening of the lockdown before going ahead with other measures.

“This is sensible,” he said. “We will take up Mr Williamson’s statement that his door is open in order to seek to engage in discussions about a safe way forward.”