WASHINGTON (AP) _ Eighteen women custodians working in the Capitol filed a sex discrimination complaint Thursday.

``We're doing way more than the men and getting underpaid,'' said Jewel Lewis, a nine-year custodian who cleans Senate offices overnight. ``When positions come open, they know already who they want,'' barring women from moving up the ladder, she said.

The top pay is $9.90 per hour for custodians _ almost all of whom are women _ and $10.77 per hour for laborers _ almost all of whom are men _ even though they do much of the same work, said union organizer Tony Corbo, who will represent the 18 women. There are now about 300 custodians.

The Council 26 branch of the American Federation of State, County and Municipal Employees has been working since June to organize the roughly 1,800 workers in the office of the architect of the Capitol, who oversees construction, maintenance and cleaning in the Capitol building.

Ben Wimberly of the architect's office declined to comment on the allegations because they are the subject of a complaint filed with the congressional Office of Compliance.

``A lot of the women are heads of households'' and need second jobs to make ends meet, said Dolores Jones, a 10-year custodian working in House offices.

As an example of overlapping work requirements, Corbo said the custodians now regularly haul up to 50 pounds of trash during each cleaning, a job the laborers are supposed to do in addition to their light maintenance and other cleaning duties.

The overlaps have become more pronounced since many jobs that became vacant have not been filled, the women told reporters Thursday morning.

The Congressional Accountability Act, which took effect in October, requires Congress to follow the laws that apply to the rest of the country, enabling workers to organize.