Last May Nationwide was awarded a £50 million grant from the RBS bailout fund to help it move into business banking, matching its own £50 million commitment.

The building society also picked 10x Future Technologies, the fintech startup founded by former Barclays boss Antony Jenkins, to help build the tech platform for the new business current account.

Now, Nationwide says "timeframes for bringing elements of our proposition to market will extend" and that the account will launch later this year than initially planned.

"Our progress in bringing this account to market has been slower than expected," the mutual says. "Our commitment to bring the fairness and value of mutuality to the SME banking market, particularly smaller businesses is unchanged, but experience in 2019 has led us to re-assess the rate at which this can be achieved."

The company stresses that it has submitted its quarterly progress reports to the Banking Competition Remedies scheme. Last week Metro Bank had to return £50 million to the scheme after an accounting scandal scuppered expansion plans.

A new dedicated mobile app has been built but Nationwide is still working to "test and refine the experience". Meanwhile, work is ongoing on Open Banking-powered switching support.

The news will have a knock-on effect on other parts of the Nationwide business plan, with savings, loans and credit card products all delayed.

Meanwhile, talks are taking place with partners about building digital tools for business clients and the account is being linked to the main cloud accounting packages.

Branch staff are undergoing training ahead of a phased rollout later this year, with an extra 200 employees expected to be hired to support the business service.