ONE of Nicola Sturgeon’s closest allies was paid an extra £33,000 a year for leading the SNP at Westminster under a secret deal, it has emerged.

Angus Robertson, who is now Humza Yousaf’s Constitution Secretary, was paid the top-up after the SNP became the third largest party in the Commons in 2015.

The SNP confirmed there had been "senior leadership remuneration".

Scottish Labour said it showed how a secrecy culture had been left to “fester” in the SNP.

The leader of the main opposition at the Commons has long been entitled to an allowance to help them perform their extra parliamentary duties.

In 2015/16 that was worth £63,489, while Government ministers and the opposition and Government chief whips were entitled to £33,207 on top of their £74,000 MP’s salary.

The Sunday Times reported that, although he was not automatically due any extra, the SNP also decided to pay Mr Robertson the £33,207 figure.

However few SNP MPs knew of the arrangement, which later angered many of them.

The paper reported the money was taken out of public funds paid to opposition parties in the Commons, known as Short Money.

The SNP landslide in the 2015 general election, when it won 56 of the 59 seats in Scotland, meant it was entitled to around £1m in Short Money.

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Although there is no suggestion of wrongdoing - the SNP was entitled to spend the Short Money on parliamentary business as it saw fit provided it was signed off by an auditor - the arrangement was stopped when Mr Robertson lost his Moray seat in the 2017 election and Ian Blackford became leader of the Westminster Group.

Mr Robertson later switched to Holyrood, winning the Edinburgh Central seat in 2021 after an alleged party ‘stitch-up’ to secure him the SNP candidacy over MP Joanna Cherry KC.

Scottish Labour deputy leader Jackie Baillie urged the SNP to explain why the salary top-up was never registered or publicly declared.

The finances of SNP headquarters have been under investigation by police for almost two years after complaints £660,000 raised for Indyref2 may have been spent on other things.

Former chief executive Peter Murrell, who is married to Nicola Sturgeon, was arrested and questioned by detectives on April 5 before being released without charge.

Last Tuesday, then SNP treasurer Colin Beattie was also arrested, questioned and released without charge, and resigned from his party post the next day.

He was replaced by Cumbernauld MP Stuart McDonald yesterday.

The Mail on Sunday today reported the police are searching for phone sim cards which could hold clues as part of the probe.

Ms Baillie said: “This is another example of the culture of secrecy and cover-up that has been allowed to fester at the heart of the SNP.

“It is unbelievable that the SNP and Angus Robertson both failed to declare that Mr Robertson’s wages were topped up with public money.

“There must be urgent clarification about why this payment was never registered and why senior figures in the SNP went to such extreme lengths to keep it a secret not just from the public but from other figures in their party.

“Scotland deserves better than the arrogant and sleaze-ridden SNP.”

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Scottish Tory party chair Craig Hoy said: “This latest revelation is just more evidence of a culture of secrecy that has become utterly ingrained in the SNP.

“Not content with keeping the public in the dark over financial matters, for many years the SNP was hiding a £30k salary boost for Angus Robertson from senior figures in their own ranks.

“The SNP must urgently come clean and explain why this publicly-funded top-up was kept hidden for so long.

“If they are ever to regain the nation’s trust, the SNP must kick their addiction to secrecy once and for all, and finally commit to full and open transparency with the Scottish public.”

Asked for commnet, the SNP did not quibble with the Sunday Times report.

A spokesperson said: "Employment issues relating to the Westminster SNP Leader, Chief Whip and group staff are a matter decided by the group executive.

"Senior leadership remuneration followed the SNP becoming the third party at Westminster and was pegged below comparative UK government and opposition positions."