The chairmanship of the Conservative party is no longer the big-hitting job it once was. The decline in the post’s prestige and influence from the days of Lord Woolton or even of Chris Patten reflects many things. Chief among these are the disappearance of the mass party and the centralisation of power in the leader’s own office. Until recently, however, the Tory chairman in the election-dominated second half of a parliament was nevertheless still a big political player – in the previous three elections the post was held by Michael Ancram, Liam Fox and Eric Pickles, all experienced figures. Even today, the job still calls for someone with presentational credibility, who can discharge a dawn-to-midnight media role with an authority only marginally less than that of the leader.

There was surprise when Grant Shapps was appointed chairman in 2012, with the hard political pounding of the 2015 election just around the corner. Young, bright and indestructably optimistic though he is, Mr Shapps is nobody’s idea of an authority figure. Perhaps, though, in today’s professionalised political era, that inexperience might not have mattered. As long as Mr Shapps was willing to be a long-life-battery bunny on behalf of his party, relentlessly repeating the line to take on breakfast shows, phone-ins and social media, his lack of political weight might not matter, and his good-humoured lightness might even seem an asset. But now things have changed irreversibly.

Revealed: Grant Shapps' threat to sue constituent over Michael Green post Read more

The Guardian revealed on Monday that Mr Shapps was actively pursuing a second career in his early days as an MP after 2005, something he had repeatedly denied in very explicit terms. That is not necessarily wrong. Nevertheless, the practice doesn’t go down well with a pitiless public and it certainly didn’t help that he pursued that career under a false name, selling a product called Stinking Rich and boasting to clients that it offered them the prospect of “a ton of cash”. And he certainly did do something wrong when he insisted – and continued to insist even last month in an LBC interview – that he was not moonlighting as Michael Green when, as the Guardian has now shown, he clearly was, and on top of that used legal threats to force a constituent to take down an allegedly libellous post. His euphemistic admission that he had “over-firmly denied” the second job, and then his attempt to pass his denial off as a screw-up, just made it worse.

Mr Shapps is an operator. It’s what he is good at. He knew his double life was under the spotlight. He knew what was at stake when he was asked about it. Time and again he signally failed to tell the truth until he was forced to do so by the evidence. To protest against his conduct and character is not in any way, as he shamelessly alleged on Monday, to be anti-business. It is simply to be pro-truth. The truth is that Mr Shapps is a chancer in a job where credibility ought to matter, and once did. The truth is also that David Cameron has made two mistakes with Mr Shapps. The first was to appoint him chairman. The second is not to fire him. But that, bleakly, is modern politics for you.