The Scottish Government is under pressure to publish a report on the offshore industry to help inform the independence debate.
North-east Labour MSP Richard Baker said he was frustrated it was taking so long to release the findings of research carried out by the Independent Expert Commission on Oil and Gas.
The panel, appointed by Energy Minister Fergus Ewing, includes Robert Gordon University’s dean of Aberdeen Business School, Professor Rita Marcella, and Press and Journal Energy opinion writer Dick Winchester of Pipistrelle, who is also a North Sea subsea veteran.
The other two members are commission chairman Melfort Campbell, chief executive at Imes Group, and leading oil and gas economist Professor Alex Kemp, of Aberdeen University.
The group has been tasked with exploring how to implement the key principles set out in a paper titled Maximising The Return From Oil and Gas In An Independent Scotland, which was published in July last year.
Its mission is to seek evidence and input from industry to find out what they think the Scottish Government should do to ensure optimal value of offshore production is achieved.
The UK and Scottish governments have repeatedly clashed over the projected value of oil left under the North Sea.
“The government’s white paper is sadly lacking in detail on the tax regime and strategy for the industry in a separate Scotland,” Baker said.
“So this report from a group which includes industry experts should be an important contribution to the debate.
“Given the referendum is fast approaching, surely it is vital it is published as soon as possible so it can be properly scrutinised.
“Ministers should explain why it has been delayed by several months already.”
A Scottish Government spokeswoman said the report would be published shortly.
“The North Sea oil and gas industry can be assured of a stable and predictable fiscal regime in an independent Scotland,” she added.
“Unlike the damaging impact of Westminster’s volatile tax regime, which has implemented numerous changes in the tax system, including the unexpected increase in the supplementary charge in 2011, one of 16 different tax changes in a decade.”