The "dog's breakfast" of the Smith Commission should be "thrown in the bin" according to one of Scotland's leading economic commentators.

Tony Mackay whose Inverness-based consultancy Mackay Consultants produces an influential monthly bulletin, lashed out at the report brokered by Lord Smith in the bulletin published on Friday, saying that he agrees with Alastair Darling and Lord McConnell that the programme for further devolution is unworkable.

"The three of us - and many other people, I suspect - believe that the Smith Commission report should be thrown in the bin and that a new group should be set up to consider the various possibilities and make recommendations."

Elsewhere in his report Mackay takes aim at the Scottish Government and the Yes campaign's economic arguments calling them "ludicrous" and "silly", criticising the campaign for exposing itself by defying academic advice. He wrote:

"The SNP badly damaged its economic reputation during the Independence Referendum campaign in 2014 with ludicrous claims about what the economy would be like if independent. In particular they made silly claims about the expected size of revenues from the North Sea oil and gas industry."

"Their base case assumption was that the oil price would average $110 per barrel; it is currently about $65. I told various SNP politicians and officials that their oil industry assumptions, particularly tax revenues, were much too optimistic but unfortunately they continued to use them. That did a lot of damage to the party's economic credibility."

He also questioned SNP politicians' emphasis on anti-austerity, while conceding that it was a short-term political gain for Scotland:

"I have reservations about these anti-austerity policies, partly because I believe strongly that there is a continuing need to reduce the public sector deficit, both in the UK and Scotland. However, the outcome is likely to be of short term benefit to the Scottish economy because the Conservative Government will almost certainly be unwilling to reduce public spending here as much as it would otherwise have done."