DOMINIC Cummings should be “compelled” to give evidence to MPs about the controversial shake-up in Downing St, which led to the resignation of the former Chancellor Sajid Javid.

The call has come from Ian Blackford, the SNP leader at Westminster, who has written a letter to the Commons Liaison Committee – the committee of all the committee chairmen – urging it to summon Mr Cummings, Boris Johnson’s senior No 10 strategist, to explain “his handling of the UK Government’s reshuffle”.

Mr Cummings is regarded as the power behind the Downing St throne whose long-running spat with Mr Javid resulted in the Midlands MP resigning just a month before Budget Day after he refused to comply with the ultimatum of sacking all his advisers in the run-up to the creation of a new economic unit, spanning Nos 10 and 11.

For many in Whitehall and Westminster this was a naked power-grab by the Prime Minister. Rishi Sunak, Mr Javid’s deputy at the Treasury, was appointed as his replacement as Chancellor with the prospect now of the Budget being put back from March 11.

Mr Blackford said: “The amalgamation of 10 Downing St and the Treasury has come as a surprise to everyone; including to the former Chancellor.

“It is substantially in the public interest to summon those involved in designing these changes; we should know their purpose and intent.

“Dominic Cummings, Boris Johnson’s Chief Special Adviser, has been widely reported as the main catalyst for these alterations and so it’s right that he is the first to be summoned and required to answer questions on this matter.”

The MP for Ross, Skye and Lochaber added: “It is crucial that key appointed officials, responsible to the Prime Minister, are compelled to give evidence on these changes; in full, in detail and in public. I hope Parliament’s Liaison Committee is favourable to facilitating this as a matter of public interest and transparency.”

In his letter to David Slater, the Committee’s Clerk, Mr Blackford says it is a “matter of deep concern” that Mr Johnson’s planned changes to the heart of Government have taken place with no prior transparency and scrutiny and suggests Mr Cummings should be the first to give evidence to MPs at the earliest opportunity.

Quoting Commons rules, which state the committee has the “power to send for persons, papers and records,” the SNP leader notes: “Your committee has the power to summon Mr Cummings; I would urge you to use it.”

He adds: “It is crucial that key appointed officials, responsible to the Prime Minister, are compelled to give evidence on these changes; in full, in detail and in public.”

Last year, Mr Cummings, the former head of the Vote Leave campaign, was found in contempt of Parliament for repeatedly refusing to give evidence to MPs over the use of data in the Brexit referendum.

However, the finding of contempt of Parliament is a symbolic admonishment, which has led to calls for the powers of committees to be strengthened, so that they can compel witnesses to attend their evidence sessions.

Mr Cummings, who said he did offer to give evidence under oath but was ignored, attended a committee session in 2016. He later withdrew his “offer of friendly co-operation,”, saying MPs had shown more interest in “grandstanding than truth-seeking, which is one of the curses of the committee system”.

Meanwhile, Grant Shapps, the Transport Secretary, sought to downplay what many regard as Mr Javid’s forced departure, stressing how all ministers should be working hand in glove with Downing St and should not be in “different silos”.

He insisted it was “not correct” to suggest Mr Cummings was running the No 10 show.

Mr Cummings and Mr Javid clashed several times in the seven months the Midlands MP was at the helm of the Treasury. The PM’s key adviser was said to be pressing for the Treasury to turn on the spending taps, which the Chancellor was reluctant to do.

Mr Shapps denied Mr Cummings was now “all powerful” in Whitehall, pointing out how last week’s decision to give the go ahead to the HS2 high speed rail link was a project opposed by Mr Johnson’s top aide.

However, Sir Keir Starmer, the frontrunner to succeed Jeremy Corbyn as Labour leader, claimed Mr Cummings was now becoming so powerful that PMQs in the Commons should become “DCQs”.

Elsewhere, Mr Shapps suggested Mr Sunak could delay the date of next month’s Budget to give himself more time to prepare for his first major fiscal event.

The Secretary of State said ministers had still not been told whether the Budget would go ahead on March 11 as planned after Sajid Javid’s shock resignation.

He told Sky News’s Sophy Ridge on Sunday: “I know the Budget plans are well advanced but I also know Rishi…may want time. I haven’t heard whether the date of March is confirmed as yet. He is probably looking at it, I should think this week.” Mr Shapps added.