The IWGB Union lost an appeal against past judgements that classed the delivery app’s couriers as self-employed.
Deliveroo added that it is the fourth court judgement in the UK that has determined its riders work for themselves.
Concern over the status of its workforce was one of the reasons behind the company’s disastrous flotation in April.
If the riders are classified as workers and not self-employed, they will be eligible for standard workplace benefits such as paid holidays, sick leave and a pension, the costs of which might completely upend Deliveroo’s business model argued its critics.
The company has always maintained that its riders choose to be self-employed because of the freedom that status gives them to do other jobs, for instance.
Priced at 390p in the IPO, the shares rose 2.4% today to 257.5p leaving those who backed the float still nursing a bruising paper loss of 34%.