Monsoon will today attempt to smoke out the rebel shareholders trying to stop the family of founder and chairman Peter Simon moving the business off the main market and on to the AlternativeInvestment Market.

The fashion retailer is dispatching nine letters to four investment banks it believes hold about 15% of the company on behalf of nominee accounts. It has set them a deadline of noon on Thursday to reveal the identities of the dissident shareholders.

Monsoon believes the rebels, who were instrumental in preventing Mr Simon’s family from increasing its stake in the firm to more than 90%, are hedge funds who are not interested in the long term viability of the retail group.

“Basically this is dishonest because they are pretending to be concerned about minority shareholders, but they are hedge funds who hold their shares for just months or weeks,” said a spokesman for the firm.

“They are really only interested in pushing the company into a position where [the family] must buy them out.”

But a source close to the rebel shareholders hit back, accusing Monsoon of “astonishing hypocrisy”, pointing out that an AIM listing would prevent the very blue chip investors Monsoon seems to want from holding shares in the business.

“Why did they explicitly put together a bid that precluded the kind of stable investors they say they want and pushed the stock into the hands of the hedge funds?” he said.

Monsoon, however, believes that one of the main rebels, the hedge fund Paragon, holds much of its stake of more than 9% through complex financial bets known as contracts for difference with Deutsche Bank. A spokesman for the rebels – who have consistently refused to identify themselves – declined to comment yesterday.

Deutsche Bank is one of the four that will be receiving letters from Monsoon today; the others are Goldman Sachs, Morgan Stanley and UBS.