Health secretary Matt Hancock told the Commons today that data on the Covid-19 vaccine’s effectiveness in preventing hospitalizations and death in people who catch the Delta variant of the virus will be known “in the forthcoming couple of weeks.”

However that timeline means the decision to press on or delay the 21 June reopening could likely be made without knowing how well Covid vaccines work against this more-transmissable variant.

Hancock told MPs officials are working on developing the “absolutely critical” figure showing the efficacy of jabs at reducing serious diseases and hospital admissions for the Delta variant first identified in India.

He revealed the timetable after Tory former minister Mark Harper, chairman of the lockdown-sceptic Covid Recovery Group, pressed for further details.

The UK Government is expected to decide next week whether to proceed with a further easing of restrictions in England on 21 June, dubbed “freedom day” by some, amid concerns about the Delta variant.

Harper said: “The Secretary of State yesterday at the statement didn’t have available to hand the information as to the efficacy of the Covid vaccines in reducing serious disease and hospitalisation, and he made a commitment rightly to set them out today at health questions at the despatch box.

“I’m delighted in this question to give him the opportunity to do so.”

Hancock replied in the Commons: “I can set out that a single dose of the Pfizer or AstraZeneca jab offers protection of 75 per cent to 85 per cent against hospitalisation while data on two doses, currently only available for Pfizer, indicates 90 per cent to 95 per cent effectiveness against hospitalisation and 95 per cent to 99% effectiveness at preventing death.

“However, the question that ( Harper) asked was specific also to the Delta variant and I said that I didn’t have the figure in my head for the reduction in hospitalisations.

“I don’t know whether I should be glad but I can report to him that the reason for that is there is not yet a conclusive figure.

“I spoke to Dr Mary Ramsay, who runs this research at Public Health England, this morning and she told me that this figure is currently being worked on and this analysis (is) being done scientifically, and should be available in the forthcoming couple of weeks.

“It’s obviously an absolutely critical figure and I’ll report it to the House as soon as we have it.”

The Delta variant is thought to be 40 per cent more transmissible than the Alpha variant first seen in Kent which swept across the UK over the winter peak.