- Video report by ITV News Consumer Editor Chris Choi
Delivery firm Deliveroo said it is willing to pay benefits to its self-employed riders if the law is changed to allow their employees to keep the "flexibility they value".
The firm said current employment law prevents companies from giving the self-employed the same entitlements offered to other employees while allowing them to maintain flexible working hours.
Delivery riders are currently paid by work, not hours.
Union bosses have criticised the firm's stance, saying there is "nothing stopping" Deliveroo from guaranteeing their employees' rights as the law stands.
This is not the first time the company has called for a change in employment law that would allow it to offer new benefits to its riders, such as sick pay, insurance or shares for longstanding riders.
In February, the UK head of Deliveroo, Dan Warne, told the Work and Pensions Committee MPs the company was willing to pay all of its riders greater benefits but the law prevented them.
"We're restricted from providing some benefits that we as a business would like to provide" Dan Warne told MPs, indicating a willingness for Deliveroo to make pension contributions.
Giving evidence to a review by Matthew Taylor into the gig economy on Thursday, Deliveroo said extending entitlements under the current law would undermine the flexibility riders have where they are paid for work, not hours completed.
Chief executive Will Shu said: "When I founded Deliveroo four years ago, I was the only rider delivering to customers all over London.
"I still do deliveries every week so I know better than anyone the hard work that Deliveroo riders put in every day. It's only right that they're given the security they deserve whilst keeping the flexibility that they value."
Maria Ludkin, legal director of the GMB union, said: "The only people who think the law is out of date are the companies like Deliveroo, who are trying to subvert the law and exploit workers.
"The law, when properly enforced, does the job of ensuring working people are paid national minimum wage and given the most basic employment rights."
TUC general secretary Frances O'Grady said: "This reads like special pleading. There's nothing stopping Deliveroo from paying their workforce the minimum wage and guaranteeing them basic rights like holiday and sick pay.
"Plenty of employers are able to provide genuine flexibility and security for their workforce. Deliveroo have no excuse for not following suit.
Mr Taylor's review is expected to be published next week.