However, Boris Johnson told journalists that the data was “still ambiguous” on the extent vaccinations would protect the vulnerable against a “new surge” of the virus.
Some scientists have urged the Government to delay the next step on 21 June after the Delta virus variant was found to be slightly more resilient to vaccines than previous variants.
Caution needed
Johnson pointed to Office for National Statistics data of infection rates showing an increase and said this necessitated a "cautious" approach.
He added: "We always knew that was going to happen. Don't forget we always said the unlocking steps that we've taken would lead to increases in infection.”
It remains to be seen how much protection the vaccination rollout will provide against a new surge of the virus, especially for “the elderly and vulnerable,” Johnson said.
He said: "There, I'm afraid, the data is just still ambiguous and so every day we're having long sessions where we're interrogating all the data, we're looking at all the various models.
Bit longer
"And the best the scientists can say at the moment, in their guidance to us, is that we just need to give it a little bit longer.”
Health secretary Matt Hancock announced this afternoon that more than three quarters of UK adults have now had a first dose of a vaccine.
When asked about the next step of lifting lockdown restrictions, Hancock echoed Prime Minister and said it was too early for a decision to be made.
He did not rule out face coverings and work-from-home guidance remaining beyond 21 June but said those questions would be answered soon.
Businesses are hopeful that they will be able to operate without restrictions such as mandated table service and one metre plus social distancing.
Night time economy operators hope 21 June will be the date they will be able to reopen nightclubs after over a year of enforced closure.
The Government must commit to additional further support for hospitality and nightlife venues should there be a delay to the roadmap, bosses have urged.