In the face of fierce opposition from mortgage bankers and consumer advocates, federal regulators are assessing proposed mortgage rules that would include a down payment requirement of 30 percent on a certain class of loans, columnist Ken Harney writes.

“QRM-Plus” is an alternative to a much laxer proposed definition of a “qualified residential mortgage” (QRM). That definition does not include a down payment requirement at all.

The ultimate definition of QRM is crucially important to the future of mortgage finance because QRM mortgages will be the only mortgages that banks will be able to sell without being forced to take on any of their risk.

Since banks often prefer to sell loans without retaining risk, many may shy away from originating mortgages that do not fit QRM guidelines.

The Mortgage Bankers Association, which opposes the proposal, estimates that only 18 percent of people who bought homes last year would have passed QRM-Plus muster, Harney reports.