JD Sports has been forced to defend itself after staff at its warehouse claimed working conditions were “worse than a prison”.

An undercover investigation by Channel 4 has allegedly found a string of harsh working practices at the sportswear chain’s Rochdale warehouse.

Temporary workers at the Kingsway Business Park facility claim a ‘three-strikes and you’re out’ rule is being operated and staff are threatened with the sack if they sit down.

Workers are also told that other offences, such as having a mobile phone, can result in instant dismissal, Channel 4 claimed.

Some staff said conditions are “worse than a prison”, the broadcaster reported.

However JD Sports said a “large number” of the allegations are untrue, including the claim that it operates a ‘strikes’ policy. It also denied that staff can get sacked on the spot.

Warehouse working conditions in retail have been under the spotlight in the past 18 months with Sports Direct, Asos and Amazon all being criticised for their alleged ill-treatment of workers.

MP Iain Wright, who led a parliamentary inquiry into Sports Direct earlier this year, told Channel 4 he was “disgusted” by the findings on JD Sports and would like the retailer to explain itself in front of MPs.

Many staff at the warehouse are employed through agency Assist Recruitment though zero-hours contracts.

In a statement from JD Sports and Assist Recruitment they said: “We are deeply disappointed and concerned by the allegations being made which we believe are misleading and not an accurate reflection of our culture, the vast majority of our people or our standards of practice and procedures.

“Indeed, we believe a large number of the allegations put to us by Channel 4 are plainly untrue.

“Our employees are vital to our business and their welfare is an utmost priority, so we take any such allegations very seriously.

“Once Channel 4 allow access to the footage and we understand the precise nature of any allegations that do prove to be accurate, we are ready and willing to investigate them fully at the earliest opportunity.

“Where there have been individual failures or breaches of our policies we will take appropriate action, and learn for the future.

“We are sensitive to the recent scrutiny of employment conditions in the retail sector, but we absolutely refute any suggestion that we are similar and we would readily open our doors to any appropriate independent body wishing to scrutinise our operations at Kingsway.”

In September, JD Sports reported a 66% jump in half-year profits to £77.4m.