British Prime Minister Boris Johnson was admitted to hospital for tests on Sunday in what Downing Street said was a "precautionary step" because he was showing persistent symptoms of coronavirus 10 days after testing positive for the virus.
Here is some reaction and analysis following the news:
Keir Starmer, Opposition Labour Party Leader
"Wishing the Prime Minister well and a speedy recovery."
Matt Hancock, Uk Health Secretary
"Get Well Soon Boris"
Buckingham Palace said Queen Elizabeth had been informed but had no further comment.
Jeremy Hunt, Former Foreign Secretary And Ex-Conservative Leadership Rival
"Thoughts with Boris Johnson this evening. Whatever political persuasion the whole country is united in wanting our PM to get fit and well as soon as possible."
Nicola Sturgeon, Scottish First Minister
"Wishing the PM all the best and a speedy recovery."
Sadiq Khan, Mayor of London
"Sending my very best to the Prime Minister and wishing him a swift recovery."
Ed Davey, Acting Leader Of The Opposition Liberal Democrats
"Wishing Boris Johnson the best for getting through this, and a full, fast recovery. Carrie, Jo, Leo, Rachel: best of health to you. It's vital we all follow the guidance; that's how to protect you, your family, your loved ones."