With the collapse of the oil price by 40% and a further slump to $40 per barrel predicted in the New Year, alarm bells should be ringing in Westminster to take immediate action in the tax applied to the offshore industry before the industry goes into meltdown, as it did in 1986 when the price fell to that level.

Operating costs in the North Sea - owing to complicated legislation and safety priorities - are the highest in the world and the cost per barrel in many fields has now become untenable. Hard decisions will soon have to be made to achieve cost-saving cut-backs.

Dennis Forbes Grattan

Aberdeen

The use of wildly optimistic oil price "statistics" during the independence referendum campaign is a scandal and deserves a thorough investigation.

The SNP administration used these figures to argue that oil wealth would pay for a separated Scotland bonanza. Many, perhaps those most in need of help, clearly were swayed by this argument and voted Yes. At the time, more sober, neutral experts pointed out the absolute folly of projecting future prices on such a volatile product as oil. These measured comments were dismissed as coming from "fearties" and being "anti-Scottish".

Within months of the referendum we now find oil prices at half of what Alex Salmond was projecting to fund his separated Utopia. Anyone taken in by arguments of this kind in future deserve the economic disaster that will surely and inevitably follow.

Alexander McKay

Edinburgh