In a survey of its members, the Forum of Private Business found just 5% believe Alistair Darling's proposals will create an environment for their businesses to develop.
Similarly, 87% said the Chancellor's measures will not increase business and consumer confidence.
More than two thirds (70%) of respondents said they expect a more realistic budget to be delivered after the general election. And when asked how they rated the budget overall, only 10% of Forum members described it as ‘good' or ‘very good', with 52% branding it ‘average' and 38% describing it as ‘poor' or ‘very poor'.
Reflecting widespread anger at the planned hike in National Insurance rates, the Forum's survey also found that a third (45%) of respondents believed the Budget had a negative impact on employment.
However, some aspects of Mr Darling's announcement did prove popular.
Just under 9% of those surveyed said they believed the Budget was designed to encourage short-term recovery. And around 19% said the Chancellor's measures would have a positive impact on both cash flow support and business investment.
Meanwhile, a similar amount (18%) said the Budget would have a positive effect on business growth support and 14% thought it would improve access to finance.
Commenting on the findings, FPB chief executive Phil Orford said: "This research appears to support our initial assessment of the Budget - overall, it fell far short of what we were hoping for and there was a sense that it was very much a budget for the election.
"Judging from the feedback our members have given us, smaller firms don't feel that the Chancellor laid the foundations for a better environment in which to do business. At the same time, they're not taking the Budget too seriously because of the imminent election.
"However, there were some specific measures included in the Budget which should help some SMEs - things like the creation of a credit adjudicator for small firms, the extension to HMRC's Time to Pay scheme and new targets aimed at helping small businesses get more public sector contracts.
"As long as they are administered properly, these schemes should provide tangible, on-the-ground support to smaller firms and the Forum's members appear to appreciate that."
