The UK’s coronavirus vaccine rollout will receive a £1.65 billion boost to help it meet the target of offering a dose to every adult by July 31.

Chancellor Rishi Sunak will use his Budget on Wednesday to detail the plan for the new cash to aid the programme, which is a key factor in successfully easing lockdown restrictions.

Mr Sunak will also divert £22 million to fund a “world first” trial to test if different vaccines can be used together, or if a third dose is effective, the Treasury said.

NHS England has begun inviting 60 to 63-year-olds to book jabs, with nearly 20 million people across the UK having received a vaccine.

Ahead of his Commons speech, Mr Sunak said it was “essential we maintain this momentum”.

“Protecting ourselves against the virus means we will be able to lift restrictions, reopen our economy and focus our attention on creating jobs and stimulating growth,” he added.

He will also give £33 million to improve the ability to respond to new variants and improve vaccine testing, including £5 million to create a “library” of Covid-19 jabs.

That cash, like the funding for the vaccine trial, will come from the Vaccine Taskforce’s existing budget.

Meanwhile, shadow chancellor Anneliese Dodds will use a speech on Monday to urge Mr Sunak to “rebuild the foundations of our economy” to put the UK on the path to a “better, more secure future”.

And northern Conservative MPs were pressing him to go further than existing support to save the high street by permanently reducing business rates for retailers.

Forty-five Tories in the Northern Research Group called for an extension of the business rates holiday to be followed by “fundamental reform” after the coronavirus pandemic.

Led by former minister Jake Berry, they said there was a need for “levelling the playing field between bricks and mortar and online retail” by reducing from about 50% of market rent to around 35%.

Mr Sunak has also been warned the economic impact of lockdown on women is being “overlooked”, with Commons Women and Equalities Select Committee chair Caroline Nokes among a group of more than 60 female MPs and business leaders calling on the Chancellor to cut VAT for hair and beauty salons and extend the business rates holiday to the end of the pandemic.

In a letter to The Daily Telegraph, the group says the lockdown “is turning back the clock on Britain’s working women – who are not only losing their jobs at an alarming rate, but have also borne the brunt of the domestic load and home-schooling.

“These actions would show the Government’s commitment to backing business women in Britain, and that the female workforce is considered a vital part of the UK’s recovery plan.”

On Sunday, the Chancellor indicated he will extend emergency support packages, such as the furlough scheme due to expire at the end of April, as the coronavirus lockdown is unwound over the coming months.

But he said he must repair the public finances from the “enormous shock” of the pandemic with an “honest and fair” plan, with possible tax rises on the horizon.

He said that he must “level with people”, with Covid having had an “enormous hold on our economy” that will cause debt to “rise indefinitely” if borrowing continues after the recovery.

But signalling further support, he said he wants to “support people and businesses along that path” to ending restrictions steadily until June 21, as set out by Prime Minister Boris Johnson.

“We went big, we went early and there’s more to come next week,” Mr Sunak told Sky’s Sophy Ridge On Sunday.

He said he does “want to deliver low taxes” but said that “over time what we need to do is make sure our public finances are sustainable”.

Treasury sources did not deny a report in the Sunday Times suggesting the Chancellor plans to raise £6 billion by freezing income tax thresholds for at least three years.

He was said to be considering a freeze on the £12,500 point at which people start paying the basic rate of income tax and the £50,000 threshold where they begin paying the higher 40p rate, as he aims to raise £43 billion a year.

The move would allow Mr Sunak to raise extra funds without breaking the manifesto pledge that guaranteed the Conservatives would not raise the “rate” of income tax.

But it was estimated the move would push an extra 1.6 million people into a higher tax bracket before the next general election is due in 2024.