Wearing smart uniforms and carrying enormous insulated rucksacks, most of the Deliveroo riders I've seen don’t look much like the typical London bike messenger. Many of them appear to be everyday cyclists. Some ride creaky mountain bikes, others woefully unsuitable shoppers. I've seen them consulting maps on their smartphones, sellotaped to the handlebars of their bicycles.

Deliveroo is just one of many companies trying to crack the same-day food delivery market in London, but it's certainly the most visible. Last year Amazon experimented with using bicycle messengers in New York as part of their ‘Amazon Prime Now’ service, which aims to deliver goods within one hour of their being ordered. They recently began offering fresh food delivery too. Uber is trying to corner the food delivery market with ‘Ubereats’, run on a similar model to their taxi service, with self-employed owner-riders doing the legwork. But Deliveroo, armed with a start-up investment of half a billion dollars, has been the most aggressive recruiter so far.

Riders have seen very little of that money. (They aren't all cyclists; a lot of them ride scooters.) Until recently, Deliveroo riders were paid an hourly wage of £7, with a £1 bonus for each job delivered. They work two shifts – lunchtime and evening – but riders I’ve spoken to say it doesn’t really make sense to go home in between, and they often sit around outside, cold and unpaid, in the dead period. They say tips are rare.

This week the company announced what it is calling a ‘trial’ change to its riders’ contracts, which would see them paid £3.75 per job, with no hourly rate. The riders I spoke to thought it was unlikely they’d ever average more than two jobs per hour. With costs for running and maintaining their bikes taken into account, this amounts to less than the minimum wage.

Deliveroo riders and drivers went on a wildcat strike yesterday to protest against the changes. The strikers, not unreasonably, are demanding an hourly stand-by rate that would guarantee them the national minimum wage, as well as other benefits afforded employees.

Today, the riders were on strike again. Someone from Deliveroo’s management came out to speak to them, offering to discuss the new terms one-on-one. The riders said they would only discuss the terms collectively (some have already been sacked for not signing the new contracts), and dismissed the notion that the new payment scheme was only a trial.

In April, members of the Independent Workers Union of Great Britain, which has had some success pressuring traditional courier companies into paying their riders a living wage, began a test case, arguing that their employment status as self-employed subcontractors was misleading, and that riders should be entitled to minimum wage, sick pay and holiday pay. In July, Deliveroo made new riders sign contracts which tried to prevent them going to court to be recognised as employees. The IWGB case is ongoing.