That hissing sound is the Peter Costello bubble deflating.

It’s not just Michelle Grattan pointing out that Liberals are getting sick of Costello’s apparently endless indecision. You could, if you were one of Costello’s dwindling number of supporters, blame that on his crack about her needing new glasses earlier this year.

But it has spread to News Ltd, the home of the “Pete for Leader” push. The Telegraph, on the back of Steve Lewis’s scoop of some of the details of the forthcoming book, has given him a huge serve. For once – how often can you say this? — the Tele is dead right. Costello’s behaviour in recent weeks has been anything but that of a leader. The revelation that he was gulled by the oldest trick in the book — wait just a bit longer mate, and it’ll be your go — won’t do anything to strengthen his pretensions to the Liberal leadership.

Costello’s not helping himself. After months of intriguing silence, now that he’s actually saying things, it’s apparent there’s not much actually there. He came to life in the chamber the other week – before he bailed out to go to America, thereby missing the interest rate cut and the Howard shindig. But his repeated interjection of “blame game, blame game”, and claiming he had got a bigger crowd at his testimonial than the Prime Minister had at a speech, weren’t exactly brilliant stuff.

Not so easy without the bully pulpit of the Treasury benches eh Hamlet? Wilson Tuckey usually manages better than that, especially when he hasn’t taken his medication.

It’s also not a good look to go over to the United States and bag the Australian economy from afar. Malcolm Turnbull was complaining last week about Wayne Swan having done exactly that earlier this year. Costello’s incisive analysis was that “big mistakes have been made in Australia.” He didn’t actually get around to saying what those mistakes might have been.

Better to have stayed silent, Peter, and maintain the illusion of substance. Let’s hope the book has a bit more content.

Someone else who needs to seriously take a vow of silence is Tony Abbott. The Mad Monk needs to become the Trappist Monk. The bloke apparently cannot help but offer a running commentary on the leadership, which is great for the media but terrible for his party, which is getting sick of him.

A couple of weeks ago a senior Liberal complained to Crikey about Abbott’s big mouth and need for media attention, and Joe Hockey has now given him a serve too. Hockey is right — if Abbott (who also has a book to promote) wants to be a media figure, he needs to leave politics first. There’s presumably a job at The Australian waiting for him. We know Opposition is boring, Tony, but the trick is to convince the electorate you should be back in government. You’re doing the opposite.

Costello needs to end this rubbish next week at his book launch. If he takes off on his book tour without clarifying what he is doing, it will look like the ultimate self-indulgence — spruiking his book while his party flounders. His reputation will go from that of someone his party always wondered about, to that of someone his party is glad they never let near the top job.