Sir Keir Starmer said Boris Johnson should "have a word" with Tory MPs who he says have been spreading disinformation.
The prime minister said he is "very optimistic" that he can stick to his plan that he hopes will see almost all of society reopened by June 21.
The PM said he hopes to fully reopen the country and remove all limits on social contact in months, so long as the battle against Covid continues to go to plan.