Boris Johnson on Wednesday insisted he would accelerate the UK’s coronavirus vaccination programme after ministers suggested it was being held back by the capacity of the pharmaceutical companies making the jabs.

The prime minister, health secretary Matt Hancock and vaccines minister Nadhim Zahawi all said that “supply” issues had heavily influenced the pace of the programme.

The UK is currently using vaccines by BioNTech/Pfizer and Oxford university/AstraZeneca and Mr Johnson told MPs that the government was “doing everything we can to bring forward the manufacturing process so we can get it into people’s arms”.

Mr Johnson added the government was seeking to improve the transparency of the vaccine programme, including by providing regional data on jabs, after AstraZeneca said it was told by a government task force not to provide details of daily deliveries.

Earlier, the prime minister confirmed the government’s plan for a pilot scheme under which a vaccination centre will operate 24 hours a day, seven days a week, in an effort to speed up the number of jabs. But he told the House of Commons: “At the moment, the limit is on supply.”

Mr Hancock told the BBC that supplies of the vaccine were the major “rate-limiting” factor impacting the programme’s roll out.

Mr Zahawi said: “In any manufacturing process . . . it begins lumpy, it begins to stabilise, then smoothes out and that is the process that we are going through at the moment.”

But he added the government was confident of hitting its target of offering the vaccine to 15m of the most vulnerable people in the UK by February 15. Data released on Wednesday showed that 2.6m people have so far had their first dose of one of the vaccines.

The Financial Times reported on Tuesday that Mr Johnson had clashed with NHS chiefs over the pace of the vaccine programme and was frustrated at what he saw as excessive bureaucracy — although officials said relations had since improved.

Other issues affecting the programme include a global shortage of vials for the vaccine and the requirement that batches of doses made by the pharmaceutical companies must be checked for safety and quality by regulators before they are released to the NHS.

Giving evidence to senior MPs, Mr Johnson was asked what the government was doing to increase the supply of vaccines beyond what had initially been agreed with the pharmaceutical companies. These also include Moderna, although its vaccine is not due to be available in the UK until the spring.

“There is . . . a programme to accelerate the delivery of the Oxford vaccine, the remaining Pfizer vaccine is being brought forward, the Moderna vaccine as well,” said the prime minister.

Tom Keith-Roach, president of AstraZeneca UK, told the Commons science and technology committee that the company had already released more than 1.1m doses of its vaccine to the UK. “We are scaling up to 2 million doses a week imminently and we'd certainly hope to be there on or before the middle of February,” he added.

One person familiar with AstraZeneca said its 2m dose a week target — based on the UK's total order of 100m divided by 52 weeks — was achievable.

AstraZeneca did not respond to a request for comment about ministers’ statements about vaccine supply.

When pressed by MPs for information on jab deliveries, Mr Keith-Roach said that the government’s vaccine task force had advised AstraZeneca not to share in detail “daily delivery schedules and locations for security reasons”.

Pfizer, responding to ministers’ statements about vaccine supply, said deliveries to the UK were on track “and progressing according to the agreed schedule”.

It added its schedule could be affected by regulatory approvals and “manufacturing timelines”, among other things.

Additional reporting by Jim Pickard in London