The Committee questioned the witnesses on the potential scope for tax avoidance, and whether extending devolved tax collection to inheritance tax and capital gains tax would have an adverse effect on revenues.

‘Devolution will lead to greater complexity and more tax avoidance,’ warned Chas Roy-Chowdhury, head of taxation at ACCA. ‘If you want simplicity, the less you devolve the better. You can devolve a lot but it depends how far a Scottish administration wanted to change the tax.’

In the view of the witnesses, avoidance would only become an issue if there were large variances between the main UK income tax rates and the Scottish rates and bands.