In the simmering legislative debate over so-called ride hailing companies like Uber and Lyft in Massachusetts, a smaller question is bubbling up: Should those companies be required to include a tipping option in their apps?

And, more existentially, does having a tipping option help drivers—or hurt them?

Drivers for services like Uber and Lyft are allowed to collect tips, but while Lyft includes a tipping function in its app, Uber does not. There has been some contention between drivers and Uber, meanwhile, over whether tips are "included" in the basic fare and what exactly that would mean.

A bill passed last March by the Massachusetts House of Representatives, imposing some new regulations on the ride sharing companies, didn't address the question of tipping.

A different ride-hailing bill now being debated in the State Senate, widely viewed as more favorable to the industry, does contain a clause mandating those companies include an option to tip in the app itself—a requirement that would presumably require at least Uber to change its model somewhat.

The bill requires that a ride hailing company "includes the option for a rider to provide a tip to a transportation network driver through the transportation network company’s digital network application."

Two amendments to the Senate bill, however, seek to remove that provision.

State Sen. William N. Brownsberger (D-Belmont), the sponsor of one of the amendments removing the tipping language, told WGBH News in a statement: "The bill is about public safety, we shouldn't be wading into labor relations."

Speaking on behalf of state Sen. Kenneth J. Donnelly (D-Arlington), who sponsored the other amendment removing the tipping language, chief of staff Cindy Friedman told WGBH News that the senator isn't necessarily for or against mandating tipping—but that the amendment was to "put a pause on what the senator saw in the bill that he didn't expect, which was a section that addressed an issue around working conditions—which is, do you get tips or not. His understanding was this was a consumer protection issue."

"Tips, in general, can be very good, and they can also be very bad, because there are lots of industries, lots of companies that say, 'Hey, my workers are getting tips so I don't have to pay them much,'" said Friedman, noting that Donnelly also introduced an amendment expressly allowing drivers for ride-hailing companies to engage in collective bargaining.