Boris Johnson facing Commons broadside from Sajid Javid after he quit as Chancellor

Former Chancellor Sajid Javid departs following the weekly Cabinet Meeting within number 10, Downing Street on February 06: Getty Images

Sajid Javid was today set to deliver a dramatic resignation speech in the Commons reminding Boris Johnson of the importance of a credible Treasury voice in the Cabinet.

Friends of the former chancellor believed his personal statement to MPs would also stress the importance of strong public finances, candid discussions between Cabinet ministers and respect towards officials. Mr Javid’s allies emphasised that his speech would be “constructive and positive in tone” and not intended to damage the Government and the PM, which he supports.

However, his words may be amplified by the electric atmosphere that such personal statements tend to generate. Resignation speeches by ex-chancellors Lord Howe and Lord Lamont were political sensations and stoked leadership crises for Margaret Thatcher and Sir John Major.

Mr Javid resigned in the middle of the reshuffle on February 13 when the PM tried to force him to sack his team of four special advisers and accept a new economic unit run jointly with the Prime Minister’s office.

Boris Johnson, flanked by new Chancellor Rishi Sunak (POOL/AFP via Getty Images)

His departure, which sent shockwaves through the Government, followed tensions over Mr Johnson’s wish to raise spending in order to “level up” the regions, and friction between Mr Javid and the PM’s maverick senior aide Dominic Cummings.

The former chancellor planned to stand up after the weekly Prime Minister’s Questions this afternoon while Mr Johnson is in the chamber. His speech was expected to be brief.

“He’s not trying to bring the Government down,” said a friend. “But he does believe a Prime Minister needs their Chancellor to give them honest advice and that good Cabinet government depends on that.”

With successor Rishi Sunak’s Budget a fortnight away, any comments by Mr Javid about the public finances will be seen as highly significant.

He fought hard during the general election to have fiscal rules in the manifesto to curb borrowing for current spending. Today the respected Institute for Fiscal Studies pointed out that if the Prime Minister drives up overall spending without raising revenues, the fiscal rules will be the shortest-lived in history.

Mr Javid resigned as Chancellor in the Cabinet reshuffle (PA)

If Mr Javid expands on his past views about the importance of protecting future generations from debt, he will be established as the most powerful voice on the Tory backbenches sounding caution about the long-term economic and political perils of overspending.

Mr Javid’s circle made clear he did not intend his speech to be seen as an attack on the Government or the Prime Minister.

However, personal statements have in the past had a bigger impact than their authors intended once delivered in a highly-charged House of Commons.

The most famous in modern times was Lord Howe’s personal statement in 1990. Margaret Thatcher flinched at his most cutting line, that ministers sent to Europe felt like batsmen who discovered “the moment the first balls are bowled, that their bats have been broken before the game by the team captain”. Lord Howe was said to have been surprised by the reaction to his speech, which is seen as a precursor to Baroness Thatcher’s downfall.

Another former chancellor, Lord Lamont, damaged John Major’s leadership with the charge that his government was “in office, but not in power”. The pair reputedly never spoke again.

Robin Cook’s resignation on the eve of the Iraq invasion in 2003 saw him give an electrifying and forensic analysis of weaknesses in Tony Blair’s case for war to topple Saddam Hussein, which earned a rare round of applause.

Boris Johnson’s statement after quitting as Foreign Secretary in 2018 saw him accuse Theresa May of having “dithered” and “burned through negotiating capital” over Brexit. He also set out his rival vision, setting in train his own leadership bid.