Legislators leading the push against a proposed mortgage lending regulation are among the biggest beneficiaries of campaign dollars from the industries decrying the rules.

Industry groups such as the National Association of Realtors, the National Association of Home Builders, along with consumer advocates, have opposed the rule--required by the Dodd-Frank legislation and intended to prevent financial institutions from writing risky mortgages and then selling them to other investors--since they were unveiled in March. 

Recently, an unlikely coalition of advocates and industry groups has formed, calling itself the Coalition for Sensible Housing Policy and issuing a white paper criticizing the ...