The bank says the money will be spent on branch refurbishments, faster account opening and simplified mortgage processing. The state-owned institution also intends to introduce a better complaints handling system and consolidate customer data with analytics to provide an improved single view of each customer across its complete product range.

On the high street, RBS says it will build a 'branch of the future' proposition and roll-out self-service formats for each region, with a strong emphasis on the automation of routine transactions.

The banks say it will also continue to invest in its digital business, describing online and mobile as "key distribution channels". Over the past year, the bank has seen online sales rise by 25%, with active online banking customer up 11% to 5.2 million.

Growth in the mobile channel has been even more impressive, with the number of active users doubling from one million to two million by end-2012. RBS says its mobile users log in on average six times per week, compared to twice a week online.

The bank is currently trying to sell off 315 of its branches as a condition of its multi-billion pound government bailout at the height of the financial crisis. An earlier deal with Banco Santander fell through over unspecified 'IT integration' issues.

A deadline for fresh bids closes this Thursday. Former Tesco bank chairman Andrew Higginson is said to have raised £1.3 billion from a consortium of blue chip investors to table a bid as the platform for the launch of a new bank. Other bidders are also understood to include Corsair Capital and US private equity firm Centrebridge Capital, and a rival PE team comprising JC Flowers and Apollo.