The group representing Uber drivers in New York City has launched a petition calling for the e-hail company to offer in-app tipping.

The online petition, launched Thursday by the Independent Drivers Guild, quickly surpased 1,000 signatures from the city’s pool of about 35,000 Uber drivers.

The guild hopes to put pressure on Uber to add a tip feature to its app as part of a larger public awareness campaign to remind customers that tips aren’t factored into drivers’ pay.

“In-app tipping would be a clear path to put thousands of dollars back into drivers’ pockets,” said Jim Conigliaro Jr., founder of the guild, a joint project between the Machinists Union and independent Uber drivers. “Drivers in the industry—especially drivers in the industry before Uber—derived a lot of income from tips.

“Taxi drivers have always been tipped at the end of ride,” he continued. “Black car companies typically would include tips as extra line item in their vouchers—it’s always been a part of the for-hire vehicle industry.”

The guild will be rallying over the next month, handing out flyers and distributing bar napkins with text declaring that Uber customers should be able to tip their drivers as easily as they could tip their bartenders.

Uber, which just reached its 100 million trip milestone in the city, has been criticized in the past for not including a tipping feature on its app, though the company has long defended the policy as one of the core tenets of the service.

“On Uber, tips are not included, nor are they expected or required. Riders tell us that one of the things they like most about Uber is that it’s hassle-free,” said Uber Spokeswoman Alix Anfang in a statement. “Riders are free to offer tips and drivers are welcome to accept them, as has always been our policy.”