Uber is challenging a landmark ruling that says it must give drivers employment benefits.
James Farrar and Yaseen Aslam won a case against the ride-hailing app last year after arguing they were workers and entitled to the minimum wage, sick pay and paid holiday.
The company is appealing against the judgment, saying it could deprive drivers of the “personal flexibility they value”.
It comes at a time when the firm is under pressure, battling Transport for London over a decision to strip it of its right to operate in the capital on the grounds it is “not fit and proper”.
Image: James Farrar (L) and Yaseen Aslam (R) won a case against Uber last year
Dinah Rose QC, representing Uber, told an employment appeals tribunal in London that the licence decision was not relevant to the case.
Referring to the number of reporters present, Ms Rose told Judge Jennifer Eady QC: “If this tribunal feels a little crowded today, it’s for good reason.
“There are two elephants in this room – the first is the decision made by Transport for London last week.
“Uber has made a public statement in that decision. It’s not relevant to this appeal and I don’t propose to address it any further today.”
The firm claims it is an agent for drivers – not an employer – and therefore does not need to offer benefits.
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Speaking at a demonstration ahead of the hearing, Mr Farrar rejected this and said he hoped the initial judgment would be upheld.
He told the crowd: “If we can win this case in the court today, if we can beat Uber back, if we can prove drivers working for Uber should have their workers’ rights that will be absolutely ground-breaking.”
Jason Moyer Lee, general secretary of Independent Workers Union of Great Britain, said the final ruling could set a precedent affecting millions of others.
“Out of all the companies in the so-called gig economy, Uber is probably the one with the biggest stomach for the fight.
“So if Uber keeps losing you’re going to have smaller companies in the so-called gig economy accept that the lay of the land is worker status for these people.
“If we win enough of these cases, the companies will stop fighting and will give the minimum wage, holidays and pensions from day one.”
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Judge Eady will hear a second day of arguments before retiring to consider her ruling.
It could be months before a final decision is announced.