Life’s a beach if you’re Queens Borough President Helen Marshall, who spends more time in the Hamptons than the halls of government, sources told The Post.

Marshall, 82, has been AWOL since June, claim Borough Hall insiders.

The three-term lame-duck Democrat is “just blowing it off,” observed a shocked source who said Marshall summers in Sag Harbor, where she keeps a tidy one-story home.

“She won’t be back to work until September 15th!” the source gasped.

And insiders say her absenteeism has hurt Queens.

“She is supposed to be the ambassador of the borough,” said one political source. “All that she’s really done is some ribbon-cutting. It’s actually pathetic.”

Marshall rakes in $160,000 a year. She doesn’t receive a specified set of vacation days, according to the City Charter.

“Her reputation is she’s very MIA,” charged one Queens pol. “She’s a very low-maintenance borough president — that’s been her whole career, but now that she’s getting older and her term is coming to an end, that might be even more the case.”

When confronted with the claims, Marshall grew fiery, at first denying them and then claiming she’s been working from her East Elmhurst home.

“I think I’m doing my duty,” she offered. “I’m in touch with the office every day of the week.”

Marshall declined to say how many days of the week she spends at home but said she’s working there because her husband, Donald, is ailing and had serious spinal surgery this summer.

“Do you know what kind of pressure I’ve lived under?” she said. “I sometimes have to do work at home and also take care of my husband.”

Marshall said all of this has caused her to fall behind on housework but denies she has shirked her beep duties.

“If anybody calls to make an appointment with me, I will be there,” she vowed.

Marshall’s staff did not provide her official schedule. Her official Web site tracks her public appearances — a total of eight days of photo-ops since June.

Insiders said Marshall has had a long history of absenteeism.

Former Queens Borough President Claire Shulman said she always viewed the post as a 24/7 job.

“I was in the office most of the time,” she continued, careful not to criticize Marshall, a former member of the City Council and Assembly. “I took weekends off here and there, but I don’t remember being away a lot.”