With less than 30 hours left before a possible government shutdown, anxious government workers and their families packed into an Alexandria auditorium Thursday night to vent their frustrations and find out what they should expect in the crucial coming days.

The town hall meeting at Francis C. Hammond Middle School on Seminary Road was convened by Rep. James P. Moran Jr. (D-Va.) for the purpose of “educating and preparing our federal workforce” for a shutdown. The event, which drew more than 200 attendees and a horde of reporters, was thrown together in a day.

“We called this on an emergency basis because I think we have an emergency,” Moran said, predicting that “there very well may be a shutdown of some time” that would lead to the furlough of about 800,000 federal employees, and 100,000 from the Washington area.

As the possibility of a shutdown has become clearer, federal employees have eagerly sought answers: Will they work during a shutdown? Who will decide? Will they receive back pay if they do work? Northern Virginia is also home to a huge number of government contractors, who have their own set of worries.

“I happen to be on a federal grand jury,” one attendee said before the event. “We’re scheduled to meet next week. Are we going to meet?”

Moran warned that although many federal workers assume they will get back pay in a shutdown, “the main thing I should let you know is you should not take that for granted. . . . At this point in time there is little sentiment [in Congress] to reimburse those employees who have been furloughed.”

And he advised federal workers “to start conserving whatever financial resources you have.”

Joseph Lipari, 59, has been a government worker for more than 40 years. An Air Force employee, he is detailed to the Combined Federal Campaign, which coordinates charitable donations across the government. Lipari said he expects to be furloughed in the event of a shutdown.

Lipari recalls the 1995 shutdown clearly.

“We were just grateful that we got paid,” he said, adding that back pay was high on his list of concerns this time around. “The mortgage companies aren’t going to cancel your mortgage [payment] just because you didn’t get paid.”

Although a shutdown would affect every region of the country, Northern Virginia could be considered Ground Zero if one occurs. About 70,000 federal employees work in Moran’s 8th District — the most of any congressional district in the nation — according to numbers compiled by the National Treasury Employees Union. The neighboring 11th district, represented by Gerald E. Connolly (D), has 58,000 federal workers.

The event drew a mix of spectators. Barbara Wilson, the wife of the late congressman Charlie Wilson (D-Tex.), was on hand because she has two daughters working for the government — one works for the federal bankruptcy court in Tampa, and the other is a civilian employee at MacDill Air Force Base in Florida and a member of the Army Reserve.

The second daughter is working in Qatar and was scheduled to be there for two weeks but will have to cut her stay short — and waste the work she’s done — if there’s a shutdown.

“They’re sending her home Monday,” Wilson said. “It’s horrible,”

Win and Jane Singleton of Falls Church attended because they have a brother-in-law in the U.S. Forest Service, a daughter in the Army and a father who is an Air Force veteran who depends on retiree benefits.

Jane Singleton complained that a government shutdown “is not a reasonable solution” to the government’s problems.

“It’s taking it out on a certain group of people,” she said of government workers. “No other group of people would take this kind of singling out without protesting.”

Although Moran and other lawmakers have advanced legislation that would prevent members of Congress from getting paid during a shutdown, that was cold comfort.

“Most of the members of Congress don’t need to worry about their next paycheck,” Win Singleton said.

Even before finishing his opening remarks, Moran was sharply interrupted by members of the audience. One asked why Democrats hadn’t completed a spending bill for 2011 last year, when they still controlled both chambers of Congress. Moran didn’t answer but said he wasn’t there to “argue or defend any of this.”

Two attendees asked whether furloughed federal workers would qualify for unemployment benefits. Moran said the answer wasn’t clear yet — it depends on how long a shutdown lasts.

Dina Long of the NTEU told the audience that help for financially struggling federal workers could be found at the Federal Employee Education & Assistance Fund’s Web site . J. David Cox of the American Federation of Government Employees said he hoped that mortgage lenders and credit card companies would show “compassion” to furloughed workers.