WASHINGTON — A senior Senate staff member is accused of trying to tug open a junior aide’s wrap dress at a bar; she said he asked why she was “holding out.” A former aide says a congressman grabbed her backside, then winked as he walked away. A district worker said a House member told her to twirl in a dress for him, then gave her a bonus when he liked what he saw.

As the nation at large deals with lurid stories of sexual harassment, Congress is only beginning to grapple with tales of sexual aggression that have long been fixtures of work life on Capitol Hill. On Tuesday, the Committee on House Administration will convene a hearing on harassment in Congress, putting the halls of the Capitol under scrutiny alongside the hotels of Hollywood, the kitchens of New Orleans, the board rooms of Silicon Valley and the suites of New York’s media giants.

In the run-up, about 1,500 former Capitol Hill aides have signed an open letter to House and Senate leaders to demand that Congress put in place mandatory harassment training and revamp the Office of Compliance, the legislative branch’s opaque in-house adjudicator.

“The Congress of the United States should be the one work environment where people are treated with respect, where there isn’t a hostile work environment,” said Representative Jackie Speier, Democrat of California, who will testify on Tuesday about her efforts to deal with harassment in the Capitol. “And frankly, it’s just the opposite. It’s probably among the worst.”