Small firms believe Britain’s tax system is deeply unfair and urgently needs to be simplified, new research has revealed.

A poll carried out by the Forum of Private Business (FPB) found that more than two-thirds of SME owners believe the tax burden placed on them is unfair - and more than half think the tax system favours big companies.

The research has been released just ahead of the January 31 deadline submission of self-assessment forms on the HM Revenue and Customs website.

It was compiled by canvassing SME owners through the FPB’s Tax and Budget Member Panel, which serves as a dedicated, subject-specific opinion-taker.

An overwhelming 43 per cent of respondents to the panel said ‘fairness’ should be the main priority for the tax system. The next popular priority was ‘simplicity’, which was supported by one in five smaller businesses, echoing widespread anger with a system which is among the most complex in the world.

Additionally, 13 per cent said they want to see the tax system reformed to make Britain more competitive internationally.

And in more general terms, 45 per cent of respondents said their tax burden was a ‘very serious’ issue for their firms.

Commenting on the findings, FPB spokesman Phil McCabe said: “Our members believe that they are bearing an unfair tax burden because of the moderate sizes of their businesses.

“The complexity of the British tax system is not only time-consuming and frustrating, it also puts small firms at an instant disadvantage. Big companies have the expertise and resources to understand the system and minimise their tax burden. For most of our members, hiring an outside tax consultant represents a significant cost few can afford, especially in the midst of a recession.”

McCabe added: “Whichever party comes to power at the general election, we would like to see them lay the foundations of a bold new tax environment where small firms are rewarded, rather than unfairly penalised, for the huge contribution they make to the British economy.”