Labour leader Sir Keir Starmer and Boris Johnson have faced each other at Prime Minister's Questions.
Sir Keir began by saying the PM's comments about care homes - in which he said too many "didn't really follow the procedures" - "caused huge offence".
The Labour leader asked if the prime minister would apologise for his remarks.
"The last thing I wanted to do was to blame care workers," replied Mr Johnson.
The PM said care workers "worked incredibly hard during this crisis", adding he took "full responsibility for what has happened".
Sir Keir Starmer responded by saying the PM had not apologised and it "just won't wash".
He said it was "clear" what the PM was saying in his comments about care homes.
Sir Keir accused the PM of "rubbing salt into the wounds of the very people for whom he clapped" by not apologising.
He asks what the prime minister will say to care workers who feel let down.
Boris Johnson replies "this government appreciates the incredible work they have done."
"We will invest in our care homes and we will reform the care home system," he promises.
The PM emphasised that asymptomatic transmission of the virus was not properly known at the start of the pandemic, and guidance was changed after it was discovered.
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