Nationwide, the giant of the building society sector, saw its share of net mortgage lending fall to just under 30 per cent in the first nine months of 2014, down from 75 per cent a year earlier, as banks returned to the market.

It won 8.6 per cent of current account switchers, lifting its overall market share from 6.2 to 6.7 per cent.

The society, which rescued the Dunfermline in 2009 and scrapped the brand in 2013, said it would continue to roll out Nationwide Now, which connects members to mortgage, personal banking and financial consultants via a high definition video link.

Graham Beale, chief executive, said: "By the end of the financial year we will have rolled out Nationwide Now to 160 branches with significant further roll-out next year and, in the process, we will have created approximately 200 new jobs nationally."

The society said three branches in Scotland were so far offering the service.

Nationwide followed its 83per cent uplift in underlying profit in the first half with a 79per cent rise to £963million, and a 105per cent increase in pre-tax profit to £946m, for the nine months compared with a year earlier.

Its underlying cost-income ratio reduced by 3.7 points to 50.1per cent, and its capital ratio increased by 4.8points to 19.3per cent.

The interest margin, or gap between lending and deposit rates, which had jumped from 1.13 to 1.48 per cent at the half year, edged up to 1.49 per cent, from 1.17 per cent a year earlier.

The rise was said to be due to "lower costs of funding reflecting market trends".

Nationwide's retail director Chris Rhodes told The Herald in November that savings rates had fallen "because ultimately we can't be an outlier and take huge volumes of savings without being able to lend sensibly in the mortgage market", and that compared with the banks, the society operated on a "fundamentally lower margin."

The society said yesterday that market deposit growth continued to exceed net lending, reducing competition for retail funds so keeping savings rates depressed. It went on: "The launch of the National Savings and Investments (NS&I) '65 Plus Pensioner Bonds' in January 2015 has impacted savings balances across the industry. Nationwide's savings outflow has been in line with management's expectation based on our share of the over-65 savings market segment."

Nationwide said it had stretched its lead as "independently ranked number one for customer satisfaction within our high street peer group" and was the only high street financial services provider within the top 30 companies in the UK Customer Satisfaction Index, improving its ranking to sixth out of 196.

Mr Beale said: "In December 2014 the PRA published stress test results for UK banks. Nationwide was able to meet the stress test without any regulatory requirement for further capital actions, demonstrating the underlying strength of our balance sheet. As a mutual, we are firmly committed to meeting the needs of our members and our performance is testament to this."

He added: "During the quarter we launched FlexOne, a current account designed specifically for the youth market, which offers a range of interactive educational tools to help young people feel confident when managing their finances."