On the day Yorkshire Building Society announced a raft of mortgage deals which undercut the Government’s Help to Buy scheme offers, its former boss was defending his role in the creation of a ‘super mutual’ at the Co-operative Group.

Former Co-operative banking chief David Anderson, who ran the Bradford-based Yorkshire Building Society until 2003, was responsible for steering through Co-op Bank’s ill-fated merger with the Britannia.

Mr Anderson told MPs he did not believe that a £550 million write-off ascribed to the Britannia’s commercial loans was enough on its own to sink the bank following the tie-up in 2009.

Instead, he characterised it as one of a series of problems that added together brought the bank to the brink of disaster, before being tipped over the precipice by a change by Bank of England regulators to rules governing banks’ capital requirements.

Mr Anderson told the Commons Treasury Select Committee that he took responsibility for initiating the merger.

He said: “I fully accept that the deal turned out to be not as attractive as we thought it was going to be – but I don’t believe it brought down the bank.”

He said that three years after the merger, the bank was hailed in a Treasury report as a “strongly capitalised mutualised business”.

“For some considerable time afterwards, this didn’t look like a daft thing to do,” Mr Anderson told MPs.

“I believe it was the right decision to take at the time given the information that we had.”

Meanwhile YBS, which has not joined the Help to Buy scheme aimed at boosting home ownership, has launched a flood of new five per cent mortgage deals which undercut products being offered by the Government’s flagship scheme.

Its range of 36 two-year and five-year fixed-rate products has raised the choice of five per cent deposit deals on the market by 56 per cent.

They are being offered to first-time buyers and home movers. Remortgage customers will also be able to take them out from 2014.

The society said recent consumer research it carried out suggested that a quarter of first-time buyers, home movers and remortgage customers would prefer to take out a mortgage in the “traditional” way direct from a lender rather than using Help to Buy.

Chris Pilling, YBS group chief executive, said that the society supported the intentions of Help to Buy.

He said: “We are delivering on the aims of this scheme without relying on Government support and offering even greater choice for borrowers.”

The society, which has a 3.6 per cent share of the mortgage market, has no plans to take part in Help to Buy as it believes its products already meet the scheme’s intentions to help credit-worthy borrowers with low deposits.