Boris Johnson is set to miss his own target to announce plans for the rollback of social distancing rules by the end of this month.

Hopes of providing early clarity on the way forward for measures such as mask-wearing and the one metre-plus rule have been dashed by the surge in cases of the Indian variant of coronavirus in the UK.

The official green light for the fourth and final step in England’s relaxation of lockdown rules is not expected until 14 June – a week ahead of the earliest date for the removal of restrictions on 21 June.

But the prime minister last Friday he would “try and let people know by the end of the month about exactly where we think we’ll be on 21 June”, sparking expectations of an announcement before May ends next Monday on the conclusions of two separate reviews into social distancing measures and vaccine certification.

Downing Street today declined to put a date on the announcement, saying only that it would be made “as soon as possible”.

“We need to get the latest data on the variant first identified in India, particularly on issues such as transmissibility and its links to hospitalisations,” said Mr Johnson’s official spokesperson. “That will allow us to make final decisions.”

The spokesperson added: “With new variants such as this, and the need to gather as much data as possible to inform our decisions, it’s right to take the time to get that information before making those final decisions.”

With a bank holiday on Monday, it is now thought that an announcement will not come before the start of June.