Boris Johnson says it is "vitally important that we get our children back into the classroom to learn and be with their friends".

Boris Johnson visited a school in Kent last month. The prime minister has said pupils' "life chances" will suffer if they do not return to their classrooms for the start of the new academic year.

The statement by Boris Johnson is part of a government effort to convince concerned parents it is right to send their children back when schools reopen around the country.

It follows advice from the UK's four chief medical officers which said "very few, if any" children would come to long-term harm from the virus by attending school, while there was a "certainty" of harm from not attending.

Dr Jenny Harries, England's deputy chief medical officer, told Sky News on Monday the risk of catching seasonal flu or being involved in a road accident is "higher" for children going to school than contracting coronavirus.

Thanking schools for their work to ensure classrooms are COVID-19-secure, Mr Johnson said: "We have always been guided by our scientific and medical experts, and we now know far more about coronavirus than we did earlier this year.

"As (England's) chief medical officer has said, the risk of contracting COVID-19 in school is very small and it is far more damaging for a child's development and their health and well-being to be away from school any longer.

"This is why it's vitally important that we get our children back into the classroom to learn and to be with their friends. Nothing will have a greater effect on the life chances of our children than returning to school."

Schools in Northern Ireland welcome pupils again today. English and Welsh schools will follow in September.

Schools in Scotland reopened earlier this month, and there has already been a small number of school closures following cases of the virus.

The Association of Schools and College Leaders and the National Education Union have called for the government to set out a 'plan B' for how education will be provided if similar local closures are required elsewhere.

Secondary school teachers in Redbridge, east London, told Sky News they need more clarity from the government.

"We're going to be exposed to minimum at least 90-or-so kids within a given day, so we could find ourselves mid-September where a number of us teachers and students alike, we could be showing these symptoms," said Bernadette Borja.

English teacher Mousufa Choudhury said: "I just don't know what the science behind it all is. I know that I'm at risk being from a BAME community, but in terms of children transmitting the virus I just don't feel like I have enough information."

Another teacher, Imran Ahmed, added: "If the rates of infection go up, do we stay open? And as staff, how do we manage that? How do we contain the virus that is spreading? I have family members that I visit quite often, including elderly parents. Am I going to stop seeing them? That's probably one of my biggest anxieties."

“I just feel helpless, that whatever I do I’m damned”

Primary head Bryony Baynes says it is a "heavy responsibility" on choosing to keep her school open, as is current guidance

“I don’t know what is best for my staff, for my pupils, for grandparents”https://t.co/MyZp1j5E4K pic.twitter.com/Nhevm2XkLX

— Victoria Derbyshire (@VictoriaLIVE) March 16, 2020

Bryony Baynes, headteacher at Kempsey Primary School in Worcester, said: "I feel there could have been more direct guidance in terms of exactly what to do for example if someone becomes poorly, if someone catches the virus, or even if there is a suspected case. And that guidance has not been clear."

Liberal Democrat education spokeswoman Layla Moran urged the government to rapidly upscale Test and Trace and ensure schools have the mental health support they need ahead of opening fully.

She told Sky News: "The best thing that Boris Johnson can do is come and address the nation, and tell us how you are on top of this.

"Are you working with teachers and headteachers to ensure this second reopening of schools is going to go better than the first?

"Tell us about what plan B is going to be because we were promised a world beating test-trace isolation system by 1 June, and we still don't know where that is."

Labour leader Sir Keir Starmer told The Observer newspaper that the chance of schools reopening was at "serious risk" because the Department for Education had spent recent weeks dealing with the controversies around exam results rather than putting plans in place.

Ms Moran added: "The government must rapidly upscale Test and Trace and ensure schools have the mental health support, financial resources and the use of community spaces they need ahead of opening fully.

"The country, and seemingly the prime minister, has lost faith in [education secretary] Gavin Williamson.

"To restore confidence among parents, pupils and teachers, the best thing the prime minister could do is sack him, rather than speak for him."