Hundreds of workers who were excluded from a bonus scheme because they were on zero-hours contracts are taking legal action against their employer.
According to the Guardian, 2,000 employees at Sports Direct collectively received approximately £160 million worth of shares.
However, many workers believe the fact they were employed on less secure contracts has led to them missing out.
As a result, they are making claims worth an average of £36,000 per person, which means Sports Direct could face a costly payout if it loses the case.
The company has been heavily criticised in recent months for its use of zero-hours contracts, with Labour leader Ed Miliband among those to speak out.
He recently insisted these "Victorian practices have no place in the 21st century" and argued that businesses cannot be allowed to use zero-hours contracts as "the standard way of employing people month after month, year after year".
Mr Miliband added that Sports Direct has large profits and predictable turnover, but is a "terrible place to work" for "too many of its employees".
The government has pointed out the "vast majority" of zero hours contracts have been used by businesses in a responsible way for many years.
However, it has expressed a desire to curb the "abuse" of these contracts, with business secretary Vince Cable insisting the coalition is bringing in new laws to ban the use of exclusivity clauses.
This, he said, is because they currently stop employees from getting other jobs if they need to supplement their income.
Mr Cable stated that the government wants to "give individuals the chance to find work that suits their individual circumstances", as well as give employers the "confidence to hire and create new jobs".
He added that the government is "tightening the screws on rogue employers who try to abuse workers on zero hours contracts".
Sue Kelly, an employment partner at Winckworth Sherwood, said: "It is important to understand that, despite the definition in the draft Bill, the expression “zero hours contract” still encompasses a range of arrangements. However, whilst there are undoubtedly some highly skilled workers, whose services are much in demand, who may benefit from this type of flexible arrangement, there is a growing body of evidence that this form of contract is being used by large companies (not just struggling small employers) to cut down their employment costs.”