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WHEN senior civil servant Gavin McCrone sat down almost 45 years ago to write his report into the possible effects of North Sea oil on the economic arguments for an independent Scotland, he probably thought that his work would be made public eventually. He knew his conclusions were political dynamite, and surely they would leak.

READ MORE: This is what Westminster doesn't want you to read: The McCrone Report in full

But no. His report was not published for 30 years in an extraordinary collusion between the two main Unionist parties to suppress McCrone’s devastating analysis that North Sea oil income could provide a basis for Scottish independence.

The National:

As he wrote: “This paper has shown that the advent of North Sea oil has completely overturned the traditional economic arguments used against Scottish nationalism. An independent Scotland could now expect to have massive surpluses both on its budget and on its balance of payments and with the proper husbanding of resources this situation could last for a very long time into the future.

“For the first time since the Act of Union was passed, it can now be credibly argued that Scotland’s economic advantage lies in its repeal.”

READ MORE: We've printed the secret oil report that every Scot must read

What is truly staggering is the nature and extent of the cover-up of the report from McCrone, the head of the Government’s Scottish economic planning unit, who was commissioned to write it by the Conservative Government of Ted Heath. It was delivered weeks before the General Election of February, 1974, which brought Labour into power, albeit as a minority government.

When Labour won again in October, this time with an overall majority of three, McCrone’s report was still on the back-burner, but the game-changer in the election had been the SNP’s rise – the number of their seats went up from seven to 11, making them fourth largest party in the Commons with only two seats less than the Liberals, while their share of the vote went up to more than 30”. The slogan “It’s Scotland’s Oil” had clearly hit home.

In April, 1975, McCrone sent the paper to the new Labour Government. A Scottish Office minister who was shown it then sent it to the secretary of state Willie Ross.

The National:

Obviously thinking it would never be released, he wrote comments in the margin to the effect that the McCrone Report should be suppressed. The National has established that the minister was the late Frank McElhone, the parliamentary under-secretary of state for Scotland. Willie Ross concurred and the McCrone Report went nowhere until 2005.

READ MORE: McCrone Report: Norway gives a glimpse of what might have been

So the cover-up began and was maintained for 30 years. Want to know why? Back then, McCrone was writing at the time of the oil crisis which started in October 1973 when the members of the Organisation of Arab Petroleum Exporting Countries (OAPEC) started an oil embargo McCrone Report was buried to hide the truth about how wealthy an independent Scotland would really be targeted at nations that were supporting Israel during the Yom Kippur War.

Virtually overnight the price of oil more than tripled, and McCrone was asked “to reassess the economic arguments for an independent Scotland” as he wrote, but concentrating on the discovery of oil.

His conclusions were impartial and have never been seriously questioned, not least because he was critical of SNP policies as well as the UK Government’s economics.

McCrone wrote: “It will be shown that the whole framework within which the economic implications of nationalism were argued has indeed been altered. The importance of this is probably greater than is recognised at present by the majority of the public and it may well be, therefore, that the discovery of North Sea oil will come to be seen as something of a watershed in Scotland’s economic and political life.”

The public were being misled even then, said McCrone: “Even after its discovery the full significance of North Sea oil was not immediately apparent and it still remains in large measure disguised from the Scottish public by the Department of Trade and Industry’s (DTI) failure to make provision for a proper Government return when the fourth round of licences was issued.”

Had the UK taken a Norwegian-style approach to tax and state investment, revenue would have soared from the 1973 “take” of between £800 million and £1200m to more than £3000m.

The National:

McCrone said: “Thus, all that is wrong now with the SNP estimate is that it is far too low; there is a prospect of Government oil revenues in 1980 which could greatly exceed the present Government revenue in Scotland from all sources and could even be comparable in size to the whole of the Scottish national income in 1970.”

McCrone contended that Scotland would keep the oil from its share of the UK Continental Shelf and his conclusion was devastating: “The country would tend to be in chronic surplus to a quite embarrassing degree and its currency would become the hardest in Europe, with the exception perhaps of the Norwegian kroner.”

Two sentences in the report have often been ignored: “In the unlikely event of England leaving the EEC, Scottish access to the other countries could in time largely compensate for any restrictions that might arise on English trade.”

And: “North Sea oil could have farreaching consequences for Scottish membership of the EEC because of the tremendously increased political power it would confer.”

Even if that’s not what the author intended, the case for independence has rarely been better made.