Under its new mortgage-relief plan, the Obama administration is staking a claim that most homeowners facing foreclosure should be able to pay 31 percent of their gross income for a mortgage.

Not 50 percent or not 60 percent, as is the case with many strapped homeowners.

But 31 percent of income still is a hefty number. Historically, borrowers’ mortgage payment limit was set at about 25 percent of their gross income before deductions for taxes and other subtractions.

With car payments, credit-card debt and everyday expenses, some mortgage brokers, bankers and others say that 31 percent still is too high for many homeowners.

Over the years, mortgage guidelines have been relaxed to enable more people to qualify for loans. In a time of rising prices, buyer demand and low interest rates, the mortgage market allowed for refinancing, quick sales and home-equity lines of credit to help stretched consumers.

No more.

As sales slowed, home prices plummeted and foreclosures rose, many existing owners have been trapped. Their houses are worth much less than their loans, and their mortgage payments are killing them financially.

Experts predict a new wave of foreclosures over the year due to job losses and adjustable mortgages that will reset to higher rates and push up monthly payments.

The program announced by President Barack Obama on Feb. 18 will offer financial incentives to lenders to restructure loan payments so that they are no more than 38 percent of the borrower’s income. More details about the plan are expected soon.

According to details already released, lenders would receive $1,000 up front for each modified loan and more down the road if the borrower stays current.

The government would use up to $75 billion in economic-stimulus funds to match additional loan modifications from the lender to bring down the payment from 38 percent to 31 percent.

For a household with gross annual income of $100,000, the monthly payment at 31 percent would be about $2,600. That’s about 50 percent of take-home pay after basic federal withholding. Add utility payments, food, health insurance, car payments and other consumer debt and there is likely very little left, said Joann Hauger, executive director of Community Housing Resources. It is a nonprofit organization that provides one-on-one mortgage default and pre-purchase counseling.

At this time, 38 percent is thought of as the upper limit for qualifying, with many households paying significantly more. Thirty-one percent is considered the upper limit of conservative guidelines for loan underwriting.

Before the boom, under traditional approval ratios for loan underwriting, 28 percent of gross income was considered the maximum for the mortgage payment and 38 percent for all debts combined.

Mortgage broker Paul Klimke noted that most of the people now in trouble have mortgage payments alone that are more than 38 percent of their gross income, sometimes much more.

“That’s what got us in trouble,” Klimke said.

Many of the people whose mortgages are in trouble have a lot of other debt and couldn’t afford the payments even if they were reduced to 31 percent of their income, counselors said.â–