Craig Kelly’s jump to the crossbench leaves Scott Morrison’s government looking like the man who suddenly finds his jacket feels a little thin in the wind.

It still has a majority, but not a comfortable one.

The Coalition’s block of 76 in a House of Representatives of 151 members means it does not possess a working majority on the floor. A vote would be tied if Labor and all crossbenchers opposed it.

Its majority of one includes the Speaker, Tony Smith. He has a casting vote in the event of a tie – one that he would exercise in a procedurally conservative manner, to preserve the status quo.

The Coalition’s position is not like that of late 2018, when it fell into minority government as things unravelled after the overthrow of Malcolm Turnbull.

But losing a number makes descent into minority more of a possibility – if some unforeseen event took out another government MP. That would put it at greater risk of losing votes.

Kelly has said that, beyond supporting the government on confidence and supply, he will back it on the program it took to the election.

This gives him room to play up on a few measures, if he feels inclined, for example on any legislation relating to climate.

On the other hand, he would be unlikely to find parliamentary bedfellows on his pet issues.

Given the makeup of the crossbench, the government can be confident of its numbers, even if they’ve become a little more precarious.

Rebel Nationals would love to recruit Kelly to their party, to get an extra vote in the cause of removing Michael McCormack from the leadership. But Kelly sees himself as an “independent Liberal”; anyway, he’d have nothing to gain by joining the Nationals (which of course would restore the Coalition numbers).

The government is determined to portray Kelly’s departure in the most positive light it can find. “Good riddance”, is the official informal line.

With his passion for spruiking ivermectin and hydroxychloroquine, unproven treatments for COVID, Kelly has been deeply irritating for Morrison. The Prime Minister recently called him into his office for a dressing down, after Kelly’s spectacular corridor clash with Tanya Plibersek.

He wanted Kelly to shut up. Instead Kelly, the zealot with the contrarian cause, is now more than ever on a mission to promote those controversial drugs.

This is the second defector to catch Morrison on the hop.

In 2018 word came of Julia Banks’ desertion when she was on her feet in the House of Representatives. Morrison was giving a news conference at the time.

Kelly on Tuesday only showed his hand in the party room. He said he wanted to tell his colleagues first. But perhaps there was a touch of tit for tat after that bawling out.

For Kelly’s part, he had the choice of an attention-grabbing exit from the Liberal party, or being dispatched from his seat by the preselectors, who would have ensured he’d not be the Liberal candidate at the election.

What harm can Kelly do the government do now?

He can cast an anti government vote now and then.

He can shout his views on COVID treatments and climate change. But he’s done that often enough. Arguably, at least in the mainstream outlets, when he is not talking as a rebel Liberal, what he says on COVID will get less attention. He’ll just be one crossbench voice.

He is signalling he is likely to run as an independent at the election. If he does, he wouldn’t poll well and it’s doubtful his presence would do much harm to the Liberals in his Sydney seat of Hughes.

In what’s a painful fortnight for the government, an element of the Kelly story fed into its problems with handling allegations of rape and sexual misconduct.

A staffer in Kelly’s office, Frank Zumbo, is being investigated over claims of inappropriate behaviour in the workplace (which he denies).

When this matter was raised with Morrison’s office last year by a local reporter via email, it did not answer her.

Morrison on Tuesday said he had spoken to Kelly about both this matter and the staffer’s performance. But Kelly has kept the man on.

The government had a significant win on Tuesday when Facebook agreed, in a deal involving the Coalition making some changes to its legislation, to lift its ban on republishing news on its Australian site.

Any other time, that would have made it a very good day.