The government has refused to guarantee that all legal restrictions on social distancing will be lifted in June.
Ministers hope the last coronavirus measures can be eased on 21 June as “Step 4” of Boris Johnson’s roadmap out of lockdown.
But the plans are contingent on the progress of the vaccine rollout as well as data on deaths, hospitalisations and infection rates.
Culture secretary Oliver Dowden admitted on Sunday that he could not guarantee all restrictions will end in June.
He told the BBC’s Andrew Marr Show: "Of course they could be delayed if the situation deteriorates but at the moment we're on track."
Pressed to guarantee if this is the last lockdown for England, the cabinet minister added: "My whole experience of the past year, and I think everyone that's watching's experience of the past year, is you can't rule things out.
He added that the government has “every confidence” there won’t be another lockdown”, adding it’s “the last thing in the world we would want to do.”
The UK may have the advantage of a successful vaccine rollout to fend off the third wave but England's chief medical officer Prof Chris Whitty warned the next surge will still cause "significant numbers" of deaths later this year.
This is partly because the vaccines are not 100% effective and partly because some people will choose not to, or are unable to, get a jab.
Restrictions to vaccine supplies next month have also prompted discussions over whether the government’s plans to lift lockdown should be delayed.
Johnson insists there will be “no change to the next steps of the roadmap” despite the spiking cases in Europe and fewer coronavirus vaccines being available.
But Mark Woolhouse, professor of infectious disease epidemiology at the University of Edinburgh, told the Andrew Marr Show on Sunday that delays in the vaccination programme will slow down how quickly lockdown can be eased.
He said: "It's not just the actual number of vaccines given out but the coverage, particularly of the most vulnerable groups.
"So far we have got through a lot of those vulnerable groups, at least with the first dose, and the coverage has been excellent - in the high 90 percents.
"But, yes, if we do have delays in getting people vaccinated the second time around, that's going to slow things down.
"Although the second dose is a booster, a lot of the protection afforded by the vaccine - 80% or 90% of it - is given by the first dose, so we will be a long way there."
Watch: Johnson: 'Nothing to dissuade me' on lockdown roadmap