THE SNP leadership's "grudge and grievance" tactics fuel anti-Englishness in Scotland and undermine the independence cause, a former deputy leader of the party has said.

In his forthcoming autobiography, Jim Sillars criticised Nicola Sturgeon for thinking "she can advance towards independence best by being at constant loggerheads with Westminster". 

He also hit out at the "turgid" independence white paper published ahead of the 2014 referendum and accused the SNP of a "series of hostages to fortune" following the Brexit vote.

Mr Sillars, a former MP who served as Alex Salmond's deputy in the early 1990s, is a strong critic of the current SNP leadership. 

In an extract from his autobiography published in The Sunday Times, he wrote: "Nicola Sturgeon's view of statecraft is that she can advance towards independence best by being at constant loggerheads with Westminster, revealing it as an inherently anti-Scottish institution. 

"That fires up the party but does it serve the nation's interests? I think not. I am not sure that the First Minister's policy serves the independence movement well either."

He added: "The fact is no one sits in ministerial offices in London thinking of how to shaft Scotland. At the very worst, they simply don't give us much thought.

"That idea that deliberate 'Scotland shafting' is going on has a grip on the Yes and SNP minds, and it has led to the policy of advancing the case for independence through manufactured grudge and grievance. 

"The 'they are taking back powers' rage is an example. Grudge and grievance complaints against Westminster, combined with vitriolic attacks upon unionists via social media, make for a stupid policy."

Mr Sillars said that if the Yes campaign is to win, it will be "on the basis of persuasion – and that will require a better understanding as to why so many 'no' voters held to the Union last time and still do".

He wrote: "Unionists do not see Westminster as a malign anti-Scottish force and, in their rejection of any such claims, they become entrenched in their views and unreceptive to the idea of independence. 

"Scottish unionists are not traitors to this nation and to suggest that they are or that they are not as Scottish as 'yes' voters is a mistake."

Mr Sillars told The Sunday Times: "I don't think we should exaggerate the undertone of anti-Englishness that exists in Scotland, but it is there and the grudge and grievance tactic of the SNP leadership does play to it and keeps it alive."

In A Difference of Opinion: My Political Journey, the former politician also criticised the SNP's tactics following the Brexit vote. 

He said that by "leaping upon every anti- Brexit forecast by the Treasury, Bank of England, Institute for Fiscal Studies and English-based think tanks, the party will find it impossible to reject their damning forecasts of the consequences of independence next time, as all such bodies did last time".