They shower and shave in the morning at the gym. Dinners often are warmed up out of a can. And at night, they bunk down in the same cramped offices where, during the day, they conduct the nation's business.

For about 50 members of the US Congress, the office doubles as home -- at least while they're in the capital.

With Washington embroiled in a raging debate over taxes and spending as lawmakers and the White House try to avoid plunging over the "fiscal cliff", these members of Congress are living proof that austerity can begin at home.

They reside in their offices because they cannot bear to do anything as wasteful as rent a small apartment or stay in a hotel.

The trend began in the mid-1990s when a handful of Republican lawmakers figured out that they could save thousands of dollars on rent each year by bedding down in their workspaces.

The move is not motivated by want: baseline pay for a member of Congress is $174,000 per year.

Some lawmakers say that living in their offices helps them keep their priorities straight.

"It provides me with a reminder every morning when I wake up in my office that my home is not here -- it is back in the district," Tim Walberg, a Republican congressman from Michigan, told AFP.

"I represent a district that has sent me here to represent them here -- not to become comfortable in Washington.

"Often people think that once a person comes to Congress, they forget about what the real world is like back home," Walberg said, adding that it was good for constituents to see that he hadn't become part of Washington.

Not much work gets done in Congress on Mondays and Fridays so most lawmakers return to their comfortable, conventional houses in their congressional districts during the long, four-day weekend.

But the other three nights of the week, when they are back in Washington, these congressman call their Capitol Hill offices home.

For the past four years, Walberg at bedtime has laid his weary body on an inflatable air mattress that he stows in a closet when the new workday dawns. It is a monastical existence, interspersed with lots of time doing "the people's business," he said.

It is much the same for Joe Walsh, a Republican representative from Illinois who lost his recent re-election bid after serving just one term in Congress.

"I didn't want to live in DC, I am not a creature of DC," he told AFP, referring to the District of Columbia, the other name by which Washington is known.

"I belong to Illinois. Sleeping in my office reminds me that the job shouldn't be comfy," Walsh said.

Paul Gosar, a Republican lawmaker who used to be a dentist from a part of Arizona near the Grand Canyon, told AFP that the non-existent commute makes up for the faintly musty sleeping arrangement.

"Here it seems that people spend hours in their car just driving from their rented place in the town," said Gosar, who sometimes sleeps on a couch and whose clothes are crammed into an wardrobe.

While colleagues are stuck in commuter traffic, Gosar said he "could be here coming up with ideas and solutions for this country."

For this congressman, the decision was a no-brainer.

A studio apartment in the neighborhood cost about $20,000 per year -- a big expense for someone with three children in school and two mortgages.

He has built a small kitchen in a small windowless room on the opposite side of the corridor, outfitted with a plug-in cooker and a supply of peanut butter and energy drinks.

Like all his fellow congressional campers, Gosar showers at the Capitol gym, a facility set up exclusively for lawmakers in a building a five-minute stroll away from his office.

Washing up at the gym "forces me to do weight training every night and then I return to the office to read and prepare the next day's work," he said.

Walberg said that having home just footsteps away made him a more effective lawmaker.

"Here, there is a lot of work to be caught up. During the day, we are meeting people, constituencies, advocacy groups, lobbyists, lawmakers, voting, going to our committees, offering amendments. This job, you just run, run, run," he said.

And evenings, Walberg said, he gets to wind down "not in a hotel but... in a (congressional) building steeped in history."