Washington ? Congress’ top Democrats demanded quick action on the subprime mortgage crisis, saying President Bush has been slow to address a situation that could cost millions of people their homes.

“This is a national crisis. Too bad it’s taken so long to realize that we have a crisis,” Senate Majority Leader Harry Reid, of Nevada, said at a joint news conference with House Speaker Nancy Pelosi, of California.

Pelosi, Reid and other Democrats want Bush to appoint a special adviser to coordinate the federal response to the subprime mortgage crisis.

“The subprime crisis demands action, and we’re working to protect families who have lost their home or are in danger of foreclosure,” Pelosi said.

For two years, President Bush has sought legislation revamping the Federal Housing Administration but has not gotten anything, said Housing and Urban Development Secretary Alphonso Jackson. “To place even one family at risk is irresponsible, and Congress should stop playing politics with homeowners’ financial security,” Jackson said.

The Democrats are trying to pressure the White House and congressional Republicans into supporting their efforts to alleviate the mortgage mess.

Foreclosure filings in August more than doubled nationwide from the same period a year ago and jumped 36 percent from July, according to RealtyTrac Inc. The filings include default notices, auction sale notices and bank repossessions.

Many of the foreclosures are caused by subprime mortgages – home loans made to people with weak credit histories. Many of those adjustable rate loans start out with low interest rates, but then reset to higher rates a few years down the road, bringing monthly mortgages up to prices many homeowners cannot afford.

More than 2 million adjustable rate mortgages are scheduled to reset by the end of 2008.

Bush last month acknowledged “some unsettling times” in the country’s housing and credit markets. He has proposed expanding eligibility requirements for refinancing loans guaranteed by the Federal Housing Administration under a new program to be called FHA Secure.

Democrats say that is not enough: “If the administration does not act, then Congress should,” said Sen. Charles Schumer, D-N.Y.

They repeated their demands for the White House to support more government spending to help homeowners avoid foreclosure, to increase the portfolio caps for home-loan finance companies Fannie Mae and Freddie Mac, and to agree to their plans to modernize the Federal Housing Administration.

The government last month slightly increased the investment portfolio caps for Fannie Mae and Freddie Mac, but the action did not go as far as Democrats had hoped.

When asked what Congress was doing, Rep. Barney Frank, D-Mass. and head of the House Financial Services Committee, pointed out various bills that Democrats have been trying to move in the House and Senate this year.

The House in September passed legislation allowing the FHA to back refinanced loans for tens of thousands of borrowers who are delinquent on payments because their mortgages are resetting to sharply higher rates from low initial levels. The Senate has passed a bill that would provide $200 million to help build up the network of nonprofit groups that help borrowers facing problems with subprime mortgages.