On visit to a south London school, the PM said: “I’m hopeful but obviously nothing can be guaranteed and it all depends on the way we continue to be prudent and continue to follow the guidance in each stage.
“Genuinely because of the immense possibilities of the rollout, because science has given us this way of creating a shield around our population, we can really look at that June 21 date with some optimism.
“I think that’s how I would put it. I’m very optimistic that we’ll be able to get there.”
June 21 is the final step on Mr Johnson’s roadmap and should include the reopening of certain sectors that stayed closed even during last summer, such as nightclubs and live events.
The Government also hopes to be able to lift restrictions on live events and make a decision on whether limits can be removed on weddings.