Thousands of ride-hailing and delivery workers in the U.S. and the U.K. went on strike on Valentine’s Day, calling for higher pay and other changes to their working conditions.

In the U.S., Uber Technologies Inc. and Lyft Inc. drivers planned day-long strikes and held mid-day demonstrations at airports in several cities, including Chicago, Philadelphia, Pittsburgh, Miami, Orlando and Tampa, according to Justice for App Workers, the group organizing the effort.

Meanwhile, U.K. delivery drivers for Uber Eats, Deliveroo, Just Eat and Stuart said they would turn off their apps and refuse deliveries between 5 p.m. and 10 p.m. The group Delivery Job U.K., which called for the walkout, said on Meta Platforms Inc.’s Instagram app that the strike was “a crucial opportunity to be seen and heard by society.”

Read: B.C. introducing minimum wage, labour protections for app-based gig workers

Of eight delivery drivers who spoke with the Associated Press in London on Wednesday, all but one said they planned to halt work at 5 p.m. Several, however, questioned whether the strike was long enough to make enough of a financial dent in the businesses. “One day is not effective,” says Evadur Rahman. “If we strike more than one day — two, three, four days — they’re gonna be affected.”

Rahman, a Deliveroo driver who planned to participate in the strike, says his daily pay dropped in recent months from about £140 (US$175) for eight hours of work to around £100 ($126). He said he wanted the company to raise the minimum rate it pays per order from £2.90 ($3.64) to closer to £5 ($6.28). “They must improve the minimum pay. It’s not enough for survival in this country.”

Delivery Job U.K. said 3,000 people planned to strike, but it was unclear how many U.S. drivers would be participating. Uber said Tuesday that based on past walkouts, it didn’t expect the strike to have much impact on its operations. “These types of events have rarely had any impact on trips, prices or driver availability,” said Uber in a statement. “That’s because the vast majority of drivers are satisfied.”

Uber and other companies that rely on self-employed gig workers said those workers appreciate the flexibility of the job. But many gig workers are pushing to unionize, saying it would give them the ability to bargain over compensation, safety measures and other benefits. In November, that unionization effort saw a setback in the U.K., when Britain’s top court ruled that Deliveroo couriers don’t have collective bargaining rights because they aren’t considered employees.

Read: U.S. bill could deny gig workers minimum wage and other protections

On Wednesday, Deliveroo said it has a voluntary partnership with a union that includes annual discussions on pay and it also provides couriers with free insurance and sick pay. “Rider retention rates are high and the overwhelming majority of riders tell us that they are satisfied working with us,” the company said in a statement.

Rachel Gumpert, a spokesperson for Justice for App Workers, described ride-hailing as a “mobile sweatshop,” with some workers routinely putting in 60 to 80 hours per week. The group, which says it represents 130,000 ride-hailing and delivery workers, is seeking higher wages, access to health care and an appeals process so companies can’t deactivate drivers without warning. But ride-hailing companies say they already pay a fair wage and have an appeals process in place for deactivations.

Earlier this month, Lyft said it began guaranteeing that drivers will make at least 70 per cent of their fares each week and that it lays out its fees more clearly for drivers in a new earnings statement. Lyft also unveiled a new in-app button that lets drivers appeal deactivation decisions. “We are constantly working to improve the driver experience,” said Lyft in a statement, noting its U.S. drivers make an average of $30.68 per hour, or $23.46 per hour after expenses.

Uber said its U.S. drivers make an average of $33 per hour. The company also said it allows drivers to dispute deactivations.

Read: Uber Canada sharing details of self-directed benefits fund for gig workers