The findings were presented at an IPA conference chaired by MP Peter Luff, chairman of the cross party Business, Enterprise and Regulatory Reform Select Committee.
The IPA carried out a survey in conjunction with ISBA between November 2006 and April 2007 to present evidence to the Department for Business, Enterprise and Regulatory Reform to support the case for exemption.
It found that the regulations affect one in two pitches, and that six of the 28 agencies affected by Tupe in the survey had incurred costs averaging £101,000 for each pitch, including redundancy fees.
The regulations were implemented in April 2006 as part of an attempt to protect employee rights, but the creative industries have long argued that the regulations are anti-competitive and harmful for small businesses because of the increased costs and liabilities involved in pitching and winning new business.
The regulations require companies to employ staff who predominantly work for the client of the firm that previously held that business they have won.
Luff said: "These regulations are a very real threat and an unnecessary burden to the creative industries, with no benefit to anyone, least of all employees who end up at a disadvantage.
"Building brands matters more than ever before to the creative wealth of our economy, and Tupe is hindering this."
The conference also heard first-hand evidence from Derek Lowe, chief executive of Storm PR, which was recently involved in the first, and so far only, tribunal case since the regulations came into force.
He said: "We were the incumbent agency with an employee for whom Tupe applied. While the drawn out tribunal procedure took place she was without a job and we couldn't pay her a salary or let her use any facilities as that would have meant we were still her employer.
"We approached this from a business perspective but the human costs can be damaging. Her employment wasn't protected, she was just unfairly dismissed and paid off by her new employer, instead of proper redundancy from us".