Boris Johnson says he is “optimistic” about the prospect of a holiday season this summer, but would not indicate a date to plan towards.

Speaking to reporters today during a visit to Batley, West Yorkshire, the prime minister said: “I don’t want to give too much concrete by way of dates for our summer holidays.

“I am optimistic – I understand the reasons for being optimistic – but some things have got to go right for us. The vaccine programme has got to continue to be successful.

“We have got to make sure we don’t get thrown off course by new variants, we have got to make sure that we continue to keep the disease under control and the level of infections come down.”

He added that, once he gives more details on February 22, “people should certainly be able to plan on that basis”.

His comments – which did not specify if he was referring to overseas or domestic holidays – followed a prediction from health secretary Matt Hancock of “a happy and free Great British summer”.

All of the UK is currently under a lockdown, with people only allowed to leave their homes for essential purposes – and the Foreign Office has a campaign saying ‘going on holidays is currently illegal’.

Labour’s shadow home secretary has called for tighter border controls after a number of cases of the South African Covid-19 variant were identified in eight different areas of England.

Johnson said there were signals the government’s lockdown measures were working in terms of reducing the spread of the virus, but that it was too early to “take your foot off the throat of the beast” by easing restrictions.

“We are starting to see some signs of a flattening and maybe even a falling off of infection rates and hospitalisations,” he said.

“But don’t forget that they are still at a very high level by comparison with most points in the last 12 months, a really very high level.”