(ShareCast News) - Under-fire Sports Direct boss Mike Ashley has rounded on MPs trying to force him to appear before a commons select committee, accusing them of being "deliberately antagonistic".The long-running spat between Ashley and the all-party Business Committee became very public this week when the group's chairman Iain Wright told the sports equipment company chief he could be cited with contempt of parliament if he failed to appear before MPs.There is no clear-cut sanction for those found guilty of the charge, according to the House of Commons Information Office.The committee is demanding Ashley appear so it can question him over Sports Direct's use of zero-hours contracts and allegations about harsh conditions imposed on warehouse staff.It has not been a good week for the media-shy owner of the "pile-it-high-sell-it-cheap" retailer. The company was booted from the FTSE 100 index as investors wiped £1.6bn from its value after an investigation by the Guardian newspaper into working conditions and a trading slump.Ashley hit back on Friday, saying in a letter that he was "disgusted" by the committee's stance, which he felt was only taken to "create a media circus at Westminster".Wright's letter which was made public, showed the committee offered Ashley several dates to appear, none of which he accepted "nor agreed in principle to attend"."As you will be aware, select committees do not normally need to have recourse to our formal powers to summon witnesses in order to secure attendance; refusal to attend without good reason may be considered a contempt of the House," he wrote."Should you fail in your reply to agree to attend on one of the dates offered to you, or a mutually convenient alternative before 1 June, the Committee reserves the right to take the matter further, including seeking the support of the House of Commons in respect of any complaint of contempt."Ashley invited the MPs to visit his Derbyshire warehouse facility, but the MPs rejected the offer on the basis that it was not in line with its "commitment to transparency" - a clear snub to the Newcastle Football Club owner.It is not the first time Ashley has tried to side-step direct questioning of his business practices. The Scottish Affairs Committee summoned him to appear last year, but he said he was too busy and sent his chairman, Keith Hellawell instead.Hellawell struggled to answer questions over the sacking of 200 workers at a Sports Direct-controlled warehouse with 15 minutes notice. The taxpayer was forced to pick up the redundancy payments of 80 people, while the rest, who were agency workers, received nothing.