THE SNP have called for an official investigation into “unacceptable attacks” by Tories against the Standards Commissioner, as experts warned attempts to roll back on independence of regulators sets a “dangerous” precedent.

Boris Johnson’s government made a spectacular U-turn last Thursday after trying to block the ­suspension of Tory MP Owen Paterson for ­breaching lobbying rules. Plans to convene a new select ­committee to overhaul the ­standards system were scrapped just hours ­after Tory MPs voted the proposals through, with Paterson subsequently resigning.

Yesterday former Tory prime ­minister Sir John Major (below) launched a ­furious attack on Johnson’s ­government, saying the conduct was “shameful” and had trashed the ­reputation of Parliament. He ­suggested the Johnson ­administration was “politically corrupt” over its treatment of the House of Commons.

The National: File photo dated 28/02/18 of Sir John Major who has suggested the Johnson administration was "politically corrupt" over the way it treats Parliament. Issue date: Saturday November 6, 2021. PA Photo. Former prime minister Sir John Major

The independent Parliamentary Standards Commissioner Kathryn Stone found that Paterson had lobbied on behalf of two companies which had paid him more than £100,000 a year – Randox, and Lynn’s Country Foods. The MP rejected the findings, accusing her of making up her mind before she had even spoken to him.

Ahead of the MPs vote on ­Thursday, UK Business Secretary Kwasi Kwarteng said it was “very ­difficult” to see what the future was for Stone.

And Johnson’s former chief aide Dominic Cummings alleged the ­actions had been designed to target Stone, ahead of any ­investigations into allegations made against the Prime Minister – which was denied by Downing Street.

In a letter to UK Cabinet Secretary Simon Case, SNP Westminster leader Ian Blackford MP said it is essential that an investigation is launched into the “unacceptable attacks and conspiracy” against Stone (below) and the independent parliamentary standards process.

The National:

He said: “Boris Johnson’s government is the sleaziest in decades – and the Prime Minister is right at the ­centre of the Tory corruption and cronyism scandal that has engulfed Westminster.

“The coordinated smear ­campaign by Tory ministers and officials against the Standards Commissioner has brought the UK Government into disrepute – and made the Prime ­Minister look like he’s running some sort of corrupt banana republic.

“There must now be an ­official ­investigation into the Tory ­government’s unacceptable attacks and conspiracy against Kathryn Stone and the independent standards process – and those responsible must be held to account, including Boris Johnson and his ministers.”

READ MORE: Jacob Rees-Mogg told to step down after 'disastrous' Owen Paterson defence

Dr Samuel Power, lecturer in ­corruption analysis politics at the ­University of Sussex, said reforms brought forward by ­Johnson’s ­government tended have the ­common feature of impinging on the independence of regulators – for ­example the Elections Bill, which critics say threatens the powers of the Electoral Commission.

The now-ditched proposals for the new standards commission were criticised for having an “in-built” and fixed government majority – chaired by Conservative MP John ­Whittingdale with four Tories, three Labour and one SNP MP.

Power said: “What’s really ­dangerous is to make any reforms which affect the independence of these oversight mechanisms.

“It might not be this government that ends up misusing the new ­system – but we don’t know what future ­governments are going to be like and it makes all the easier for these oversight mechanisms to be captured.”

Giovanni Capoccia, ­professor of comparative politics at the ­University of Oxford, warned the UK ­Government’s proposals on the new standards committee would have been the “first concrete step” in the direction of Poland and Hungary.

READ MORE: Former PM slams 'corrupt' Boris Johnson government over sleaze scandal

He said: “Over the course of the recent years, both the ­Hungarian and the Polish governments have ­introduced reforms that reduce the influence of countermajoritarian powers, in particular the judiciary and the media.

“The effect of these reforms is that the government is less ­accountable for its actions, and that the ­opposition’s chances of winning elections are ­reduced.

“Reducing the power of ­independent agencies that are ­supposed to ­monitor the ­government’s actions (or those of politicians in general), either by changing their formal ­powers, or by appointing loyalists at their head, is another hallmark of liberal ­democracies backsliding towards semi-authoritarian systems.”