Starting Monday, the Freelancers Union will hit the subways with an artistic campaign to raise awareness of some problems faced by 1.3 million independent workers trying to get paid on time.

The union will run adsĀ in subways, particularly the Nos. 4, 5 and 6 trains, drawn to mimic the style of artist Roy Lichtenstein, addressing issues such as wage theft and less-than-prompt payments.

Sara Horowitz, founder and executive director of the Freelancers Union, said more than 77% of freelancers reported they haven't been paid for their work within 30 days and lose an average $6,400 a year.

"When you don't pay people, it is such a moral profound issue. We want to show the immediacy of that," she said.

Whitney Meers, freelance brand consultant from East Harlem, was in a terrible situation in December when an employer failed to pay her for her work. It took her nearly seven months and many calls but eventually she received an amount less than what she was contracted for.

"When you [repeatedly] hear the check is in the mail, you think, 'Oh my god this client isn't going to pay,'" the 32-year-old said.

The campaign has support from key figures including American Federation of Teachers President Randi Weingarten.

"The freelance economy has become the new norm for so many people trying to sustain their families. Efforts to eliminate wage theft will help hardworking people who play by the rules and rightfully expect to be paid on time without having to resort to a legal battle," she said in a statement.

Horowitz said there is City Council legislation in the works that would give the city's Department of Consumer Affairs the authority to require a contract for freelancers and damages if they aren't paid within 30 days.

City Councilman Brad Lander, who is working on the bill, said more New Yorkers than ever are contractors and can't be expected to have to fight for basic rights.

Lander will take part in a town-hall meeting at 6 p.m. Monday at Brooklyn Borough Hall to gauge the freelancing community on ways the city government can assist their needs.