Nationwide Building Society is being urged to give members “a say” over its proposed takeover of Virgin Money. Earlier this month, the lenders reached a preliminary agreement worth around £2.9billion in a deal which would challenge the Big Four banks. If this agreement becomes a reality, the new banking group would have estimated assets of around £336billion with almost 700 branches. However, a Conservative peer has reminded Nationwide that it “would be wise” to consult its 14 million customers about the deal. The building society is the last mutually owned financial institution of its size wh…