The poll, conducted by the Forum of Private Business (FPB), also found that 50% of respondents believed the recent pre-Budget report had undermined business confidence and future employment.

The research was compiled by questioning SME owners through the FPB's tax and pre-Budget member panel.

One in five said simplification should be the main priority for the tax system, while two-thirds of SME owners believed the tax burden on them was unfair.

FPB spokesman Phil McCabe said the complexity of the British tax system was "time-consuming and frustrating".

"Big companies have the expertise and resources to understand the system and minimise their tax burden," he added.

"For most of our members, hiring an outside tax consultant represents a significant cost few can afford, especially in the midst of a recession."

Bryn Oakley, a partner at small business partnership Astra Printing Group, said there is a constant swing in the way the tax system works, and this particularly affects partnerships and small companies with a turnover of under £2m.

"The burden of tax returns and payments does take up considerable time, and sorting the money out if it isn't saved up is a nightmare for all those affected in this way," he said. "The current 'merry-go-round' system definitely does us no favours."

However, Peter Wise, director at Minuteman Press Bristol, said the business had not experienced problems in terms of a sudden tax burden.

He said the company lacked the resources to employ a tax specialist and instead has a dedicated management accountant that is well-informed, vigilant and delivers tax savings where available.

 "We forecast and budget throughout the year to avoid surprises and find that submission online is straight forward even on the first occasion," Wise said.