Sports Direct has seen its share price fall nearly 9% after founder Mike Ashley saying its profits would fall for the current financial year.
According to The Times, Mr Ashley said: "We [Sports Direct] can't make the same profit we made last year."
The sports retailer reported a profit of £300 million for the year to 26 April 2015, up from £249m in the previous year.
But Mike Ashley warned: "We are in trouble, we are not trading very well."
The fall in share price comes as MPs repeat their calls for Mike Ashley to give evidence over the company's working practices after he branded the committee a 'joke'.
Mr Ashley has repeatedly rejected invitations to appear before the Business, Innovation & Skills (BIS) select committee over Sports Direct's treatment of workers, instead offering to give the committee a tour of the company's headquarters in Derbyshire. But last week, the committee ordered Mr Ashley to appear, or risk being in contempt of Parliament.
On Monday, Mr Ashley told Sky News: "The current intention is not to go, because [MPs] ought to see it for themselves.
"In my opinion, they're just showboating. In my opinion, they're actually a joke.
"They don't care about the people, they care about the business of politics."
The committee's chair Iain Wright MP said it was "telling that he chose to give his response to the media rather than to the committee directly".
MPs want to question Mike Ashley of his company's treatment of workers at its warehouses, after an investigation by the Guardian in December found that agency staff were effectively earning less than minimum wage due to extensive security checks. Other investigations found that workers were subject to heavy wage deductions for minor infringements, and those who called in sick were 'named and shamed' over a tannoy when they returned.
Following the reports, Mr Ashley said he would personally lead a review into the matter, and pledged £10m to ensuring all workers are paid at least minimum wage.