The Scottish Government must set out an honest and impartial case for independence in an eagerly-awaited White Paper on separation to be issued before the end of November, MPs have warned.

Ian Davidson, chair of the Commons Scottish Affairs Committee, said while proponents of an independent Scotland must be allowed to set out the best possible case ‘they must not simply promote a party view with public money in a Government document'.

‘A Government White Paper must be, and be clearly seen to be, totally above reproach,' commented Mr Davidson at the launch of a committee report on separation, published on 15 November.

‘Similarly, on all the big important issues such as pensions, benefits, public services, and tax collection, the White Paper must be properly costed and show what a separate Scotland would realistically be able to afford, and the choices it would have to make, rather than simply claiming that oil pays for everything,' he said.

According to the Scotland Analysis Paper on Macroeconomic and Fiscal Performance, relative to the UK generating and spending £100, Scotland's onshore economy has generated £98 while Scotland's spending is £112.

This equates to an average 9.4% share of UK public spending, which is above both Scotland's proportion of the total UK population of 8.5% and its share of national economic contribution – oil excluded – of 8.3%.

A separate preparatory study from the Institute for Fiscal Studies has suggested an independent Scotland would have to make immediate ‘fiscal adjustments' of between £3-6bn annually through tax rises and spending cuts.

Earlier this month the Local Government Association sent a pre-Autumn Statement submission to the Treasury which called for a review by summer 2014 into Barnett formula funding arrangements for the devolved nations – for the sake of fairness to England.