Britain's biggest high street banks will next week unveil a venture guaranteeing access to cash amid a furore over the closure of thousands of branches across Britain.

Sky News has learned that lenders including Barclays, Lloyds Banking Group and NatWest Group have agreed to fund the joint provision of cash services in communities which face being left without them.

Details of the project will be disclosed alongside the publication of a report on the Community Access to Cash Pilot programme, which has involved testing a range of services in eight locations.

NatWest is also among the banks involved

Industry sources on Friday described the commitment that would be unveiled next week as "unprecedented".

It is expected to cost the major banks millions of pounds annually to run.

Nevertheless, the project is being established on a voluntary basis and one insider said there was a desire for the Financial Conduct Authority to give the participating banks a statutory duty to provide continued access to cash.

The new joint venture would involve LINK, Britain's biggest cash machine network, conducting an independent assessment of prospective branch and ATM closures in the context of a local community's cash needs.

The criteria used to make the assessment would include a location's population density and its level of economic activity.

Where any closures would imperil access to cash, new services such as the provision of a shared face-to-face outlet could be commissioned.

TSB recently announced the closure of 70 more branches

This may be achieved through additional banking services in Post Office branches, or a new shared bank hub or kiosk.

LINK is to be handed £4m in start-up funding by the banks, which also include HSBC and Santander UK, to get the project off the ground, the insider added.

Although cash usage is dwindling, largely because of online payments, there remain serious concerns about the impact on elderly and vulnerable people.

The new commitment from the major banks is expected to take effect immediately.

The industry's latest wave of branch closures was announced last month by TSB, which said it would close 70 of its 290 locations across the UK.

"In recent years, the bank has seen a significant decrease in branch use, with the average number of transactions per branch falling since January 2019 and no prospect of branch transactions returning to pre-Covid levels," it said.

This week, the consumer group Which? demanded an immediate moratorium on further branch closures, citing analysis suggesting that banks "may be rushing to close branches before solutions to protecting access to cash can take effect".

In a letter to the members of the Cash Action Group, Which? called for the kind of independent assessment of impacted communities' cash needs that the joint venture appears to be ready to provide.

Which? also said that a summary of such assessments should be made public, with banks forced to pause their branch closure programmes until legislation to preserve access to cash has been implemented.

The issue of branch closures has become a toxic one for the banking industry since the aftermath of the 2008 financial crisis, when the sector was saved from collapse by the provision of hundreds of billions of pounds of state financial support.

Lenders have repeatedly cited dwindling branch usage and the soaring take-up of digital banking as trends which have made large swathes of their physical branch infrastructure redundant.

A number of commercial ventures, including OneBanks, have emerged with the objective of ensuring continuity of access to banking services for the customers of all lenders.

A spokesman for the Cash Action Group declined to comment on Friday.