It would be "completely premature" to state whether schools will reopen before the summer holidays, a senior scientific adviser to the government has said.
Speaking at today's press briefing on the coronavirus crisis, Professor Dame Angela McLean, chief scientific adviser for the Ministry of Defence, said that "so much depends on this question of how well...the measures put in on March 23 [have] worked".
Asked if schools will reopen before the summer, Professor McLean said: "I am happy to answer that by saying that there's very intensive work going on to think about all sorts of different things that we might do in the next stage.
"It would be completely premature for me to give a yes or no answer to that question, because so much depends on this question of how well have the measures put in on March 23 worked, and we can't know that this week until we see a longer run of infections that have happened since that time.
"But please be assured that people are working incredibly hard to explore those sorts of questions."
Chancellor Rishi Sunak added: "I probably can't add much to what Angela said.
"We are, in all these instances...basing our decisions on the science and what is best for controlling the spread of this virus.
"That's been our approach all along and that will continue to be our approach.
"I pay tribute to those who are helping keep our schools open for the children of key workers, that is valuable, and the work that they're doing is I believe well-supported by the Department for Education.
"But they also are owed our thanks for doing that, because that is vital at this time."