Senior oil and gas executives expect taxation levied on the industry to increase should Scotland become an independent country, according to Ernst & Young.

More than three quarters (79%) of the near 140 industry leaders and decision makers polled as part of the professional services firm's latest Grasping the Thistle report, anticipate a hike in the tax take from the UK Continental Shelf in the event of a 'yes' vote.

However almost two-thirds said the referendum debate was having no impact on North Sea investment plans, with the supply of skilled workers emerging as their most pressing area of concern for oil and gas executives, followed by cost base.

Colin Pearson, a tax partner at EY Aberdeen, said: "The current Scottish Government has consistently stated that taxes would be reduced generally or in some targeted fashion following a 'yes' vote, to promote Scotland's economic prosperity. However, the results of our survey appear to suggest that oil and gas executives presently do not believe that this would apply to them."

The report, produced with Aberdeen & Grampian Chamber of Commerce, found 61% support for the creation of a sovereign wealth fund, to spread oil and gas wealth across future generations. But the biggest group in favour - 25% of all respondents - think such a fund should be created for the UK as a whole.

More than one-third of respondents said they would reject the idea if it meant higher taxes.

Mr Pearson said: "The issue of a sovereign wealth fund appears to have struck a chord with oil and gas industry leaders and there seems to be strong support for this proposition. But this does not obviously translate into support for independence."

More than half of respondents said more information on the impact of independence was needed.

The same finding has emerged from a Forum of Private Business survey which found 60% of Scottish members saying information was still lacking in several key areas. But at present three quarters of Scottish small business owners say they would vote to remain part of the UK.

The top concern was a lack of clear information on the potential impact on regulation and taxation (cited by 73%), then transport (70%) and national resources (70%). On the economic benefit of Scottish independence, 49% of businesses saw it as a threat to the country's future economic growth, while only 17% saw it as a potential opportunity.