People aged 40 and over in England are now being invited to book their coronavirus jabs as the Prime Minister faced further calls to launch an inquiry into the handling of the pandemic.

NHS England said that text messages will be sent out from Friday to 40 and 41-year-olds allowing them to arrange their vaccination appointments.

With people aged 42 to 44 having already been texted this week it means 2.5 million more people have been invited for their jab, it added.

The expansion of the vaccine rollout comes as the latest data showed an estimated 91.5% of people aged 45 and over in England had received their first dose of Covid-19 vaccine by April 25, and just over four-in-five aged 70 and over had been given both doses.

Meanwhile two leading think tanks said that a public inquiry into the country’s response to the pandemic should be launched immediately.

The Institute for Government (IfG) and King’s Fund both disputed claims that it was the “wrong time” for an inquiry , saying the first steps could be taken without distracting civil servants from tackling the pandemic.

The IfG said that the inquiry should be established in May, giving it time to determine its terms of reference and complete preparatory work such as appointing a secretary and counsel before beginning its investigations in September after Parliament’s summer recess.

The King’s Fund’s director of policy Sally Warren said: “The suggestion that everyone in Government is too busy for an inquiry is a poor excuse.

“There are first steps that can be taken to establish the inquiry – such as appointing an independent chair or agreeing term of reference – that will not distract from the efforts of public servants responding to Covid-19.”

Her comments come a day after England’s deputy chief medical officer Professor Jonathan Van-Tam said now was not the time for an inquiry.

Public Health England (PHE) said on Thursday it had identified two new variants linked to the Covid-19 variant first found in India.

The two variants are designated as “variants under investigation” rather than “variants of concern”, such as those first identified in Kent, Manaus (Brazil) and South Africa.

PHE said it has identified 202 cases of one of the variants and five cases of the other that are “geographically dispersed in England” but there was no evidence they cause more severe disease or make the current vaccines any less effective.

The identification of the new variants comes as a new analysis showed Covid-19 case rates have dropped below 50 cases per 100,000 people in more than 95% of local areas of the UK.

It is the first time since the start of September that as many as 19 in 20 areas have seen their rates plunge below such a symbolic level.

Around one in 10 areas are even recording rates in single figures.

The analysis, which has been compiled by the PA news agency from health agency data, is fresh evidence of the combined impact of lockdowns and Covid-19 vaccines in driving down the spread of coronavirus within the community.

But the UK’s medicines regulator has warned that younger adults are particularly affected by the rare blood clotting disorder linked to the Oxford-AstraZeneca vaccine.

The Medicines and Healthcare products Regulatory Agency (MHRA) said there were 209 cases in the UK of the rare combination of blood clots with low platelet counts following being vaccinated the Oxford-AstraZeneca jab, with 41 deaths, up to April 21.

New data giving a breakdown of the jab’s side affects by age, published by the MHRA for the first time on Thursday, showed that 23 cases occurred in people aged 18 to 29, 27 in those in their thirties, 30 in people in their forties, 59 in people in their fifties and 57 in those aged 60 and above, with the age not known in the remaining cases.

The MHRA said that the data suggested there is a higher incidence reported in the younger adult age groups and advised that this evidence should be taken into account when considering the use of the vaccine.

Chief executive Dr June Raine said that no medicine or vaccine was without risk, but said the blood clots were “extremely rare”.

She added: “The benefits of the vaccine continue to outweigh the risks for most people.”

Meanwhile a survey found that around a fifth of unvaccinated adults say they will feel resentful if they do not get a coronavirus jab before their summer holidays.

The Government’s target is to have offered a jab to all UK adults by the end of July.

Some 18% of those yet to receive a vaccine said they will feel resentful towards those who have been jabbed if they do not get one before their summer holidays, according to a survey of 4,896 UK adults aged 18-75 carried out by the University of Bristol, King’s College London and the NIHR Health Protection Research Unit in Emergency Preparedness and Response.

In Northern Ireland, retailers, publicans and restaurateurs are gearing up to reopen their doors on Friday in a further relaxation of Covid-19 restrictions.

Under Stormont’s phased reopening plan, outdoor hospitality and all non-essential retail are due to resume later today after four months of closure.

Licensed and unlicensed premises can serve customers in outdoors settings in groups of six from no more than two households.