But McDonald, who took part in the lender panel round up at yesterday’s Council of Mortgage Lenders’ annual conference, was concerned the bank would not be able to find enough "regular customers".
He said: "By regular I mean not astonishingly wealthy customers, just normal people."
Guest speaker Simon Jack, business and economics presenter on BBC's Radio 4's Today Programme, joked that RBS were aiming to facilitate social good as well as a profitable business which McDonald agreed was a fair reflection.
He said:"The bank is looked upon negatively but we are doing a good thing helping people into homes.
"One of the things which makes me happiest is when I sit with one of our face-to-face mortgage sellers and I think wow what a good thing we do."
