Most smaller companies believe the Government is ignoring their concerns on Brexit, according to a new report.
A survey of over 650 owner-managed businesses showed that only 41 said ministers were listening to their views.
Accountants Moore Stephens said its study highlighted how much work was needed to convince small-to-medium sized companies that the deal to leave the European Union protects their interests.
Trade tariffs was the main concern of those polled, followed by loss of EU labour and customers.
Mark Lamb, of Moore Stephens, said the research found that the level of concern amongst business leaders over Brexit was "incredibly high".
He added: "Whilst banks and other big businesses have the influence to lobby the Government for their own special Brexit clauses, there are concerns that small businesses will be forgotten about.
"Business owners are hugely concerned about what Brexit might mean for them. The Government must take their needs seriously when negotiating the exit deal.
"Brexit could potentially impact an enormous number of issues affecting owner-managed businesses in the UK; from import and export costs, to access to labour, and grants and subsidies.
"Businesses have been given very little clarity so far on what effect Brexit might have on any of these issues."