Nadhim Zahawi, who has been sacked by Rishi Sunak after days of headlines over his tax affairs, could learn a lot from the example of one of his predecessors as chancellor.

Labour chancellor Hugh Dalton entered the House of Commons to deliver his autumn Budget on 10 November 1947. On his way in, he was accosted by a journalist who jocularly asked him what he was about to say. Equally jovially, Dalton confided a couple of sentences on the changes in taxation he would announce within minutes.

Before he finished his speech, the tidbits he had disclosed to the nosy hack were in the evening papers and the London stock market was reacting.

Dalton’s indiscretion – it was hardly an offence – cost him his front bench career. Within hours he had offered his resignation to prime minister Clement Attlee and the offer had been accepted. Though he returned to office as a minister without portfolio the following year, Dalton‘s political career was effectively over.

Comparing Dalton’s honourable and swift exit to the stonewalling stance of Nadhim Zahawi over his dealings with the tax authorities – and Zahawi’s refusal to jump before he was pushed – gives us an insight into how standards in public life have slipped in the decades since Dalton’s day.

Time was when the merest hint of a ministerial mistake or slip, whether accidental or deliberate, spelled the swift end to political ambitions. No longer.

Whatever the rights or wrongs of Zahawi’s actions, whether they were within the rules or questionable, there is one key fact the Tory party chairman cannot escape from: he committed an oversight, involving millions of pounds, that he himself has described as ‘careless’.

Politically, Zahawi’s conduct has become a never ending story that has damaged the government and revived accusations of ‘Tory sleaze’ from the Boris Johnson era. This story has gone so far and shows no sign of going away; it is a fatal distraction from Rishi Sunak’s attempts to change this narrative and govern with integrity. While the PM has finally wielded the axe, the damage is done.

Such affairs always end the same way: once the media hounds are on the scent of a wounded minister they never let go until they have secured a scalp.

As a man of honour, whatever the rights and wrongs of Zahawi’s tax affairs, for the good of the party he chairs, Zahawi should have emulated Hugh Dalton – and stepped down before he was forced out.