Takeaway delivery drivers are planning to strike on Valentine's Day to demand better pay and improved working conditions.
The action, impacting four food apps including Deliveroo and Uber Eats, is thought to involve as many as 3,000 drivers and riders on Wednesday between 17:00 and 22:00 GMT.
One cyclist taking part told the BBC their pay was "absolutely ridiculous".
Deliveroo said its riders "always earn at least the national living wage".
The action, organised by a grassroots group of couriers, many of whom are Brazilian, is intended to draw attention to what has been described as poor pay and working conditions many riders face while delivering food and groceries in cities across the UK.
"Sacrificing a few hours for our rights is essential, instead of continuing to work incessantly for insufficient wages," the group Delivery Job UK said on its Instagram page.
"Our request is simple: we want fair compensation for the work we do. We are tired of being exploited and risking our lives every day... It's time for our voices to be heard."
Aside from Deliveroo and Uber Eats, Just Eat and Stuart.com will also be affected, with couriers who normally compete across multiple apps for delivery planning to refuse to take orders.
The action will extend beyond the UK.
In the US, drivers for Uber, Lyft and food delivery firms are also set to halt work for two hours on Wednesday, according to Justice for App Workers, which says it represents more than 130,000 app drivers.
Organisers said members would not be giving any rides to and from the airport in 10 major cities, including Chicago and Miami.
Delivery Job UK claimed its delivery riders were braving the "cold, rain and absurd distances" for deliveries paying "ridiculous values", ranging from £2.80 to £3.15.
A spokesman for the group told the BBC striking Deliveroo riders wanted an increase to a minimum of £5. The other companies use different pricing structures.
"They [Deliveroo] have lowered their fees. There's no incentive anymore. On a Friday night you could make £100 over 4-5 hours, now that's gone," the spokesman said.
He also claimed couriers were exposed to "a lot of violence on the streets", especially in the evenings.
Joe, a courier in London since 2018 who plans to strike on Wednesday, said the work was "incredibly isolating" and attracted a lot of migrant workers who were unable to challenge the conditions and were "forced into it".
"Conditions are shocking," he told the BBC. "The pricing of fees is aggressive. It's hard to overstate how sophisticated these algorithms have become. The fees are absolutely ridiculous."
Callum Cant, who has written about the gig economy and is a lecturer at Essex University, said changes to fees meant couriers had seen a 40% drop in wages in real terms since 2018.
"With a minimum fee of £2.80, most might only be making three orders an hour, and then they have to subtract their costs too. Some are making £7 an hour, which in London is barely liveable," he said.
While delivery drivers are not formally unionised the GMB has an agreement with Deliveroo which, the union has said, is the first of its kind in the food delivery sector.
It includes access to education courses and a pay floor for fees, negotiated each April.
In a statement, Deliveroo said it offered its riders self-employed, flexible work, alongside protections.
"Riders always earn at least the national living wage, plus vehicle costs, for the time they are working with us, though the vast majority earn far more than this," it said.
"Riders are also automatically insured for free, covering them if they are in an accident or injured while working and receive income protection if they are unwell and cannot work."
Uber Eats told the BBC it offered a "flexible way" for couriers to earn by using its app "when and where they choose".
"We know that the vast majority of couriers are satisfied with their experience on the app, and we regularly engage with couriers to look at how we can improve their experience."
Just Eat said it provided "a highly competitive base rate to self-employed couriers and also offer regular incentives to help them maximise their earnings".
"We continue to review our pay structure regularly and welcome any feedback from couriers," the company added.
Stuart.com said it also was "committed to providing competitive earnings opportunities for courier partners".
Source: BBC
