Despite Wayne Swan’s less-than-compelling performance on radio this morning, the Opposition, and Malcolm Turnbull in particular, is mired in the fake email affair and, it seems, slowly sinking.

It’s now hard to avoid the impression last Friday’s sensational committee hearing was, like the courtroom drama it resembled, scripted or at least set up in advance between Grech and the Coalition.

Which only, in a way, makes the whole performance more compelling in retrospect.

Malcolm Turnbull, meanwhile, can’t get through an interview without refusing to answer nearly every question put to him. At least Turnbull has been willing to do some media — although still no press conference — whereas Wayne Swan only broke cover this morning. But the endless drip of questions about what Turnbull knew and when he knew it is eating away at him. You get the sense round Parliament House that the next revelation about Grech and Turnbull could break at any moment.

Turnbull, by the way, is perfectly justified in refusing to commit to assisting a broader AFP inquiry into public service leaking. No Opposition worth its salt in a democracy would support such an investigation and Turnbull should reject it as a matter of principle. But that won’t stop the Government insistently asking what he has to hide.

That the OECD produced figures last night showing the Australian economy was the best-performing in the OECD provided more substance to the Prime Minister’s argument that, having lost the economic debate, the Opposition has resorted to personal attacks. The OECD numbers are heavily based on Treasury input, but yet another external tick for the Government’s stimulus approach contrasts very well with Turnbull refusing to answer questions about his involvement with a forged email.

And the contrast is fair enough, too. The Government — of which Wayne Swan is Treasurer — and the Reserve Bank have handled the global financial crisis remarkably well given how poorly our policy establishment handled the last major global slowdown in the early 1990s. They have made a difference to the number of Australians unemployment, and likely to become unemployed, the sort of real-world outcome that, like ute-based corruption and cooked-up emails, matters beyond the fog-bound confines of Parliament House.

Speaking of contrasts, we had another one yesterday, with Rudd effortlessly doing the language thing again, this time at a reception for the Spanish royals. A few sentences of Spanish, some self-deprecation, and he looked perfectly at home. Turnbull, unfortunately confined to English and with the air of a bloke waiting for the AFP to call, didn’t look nearly as comfortable.

The Opposition’s looming problem is that it has no answer to the question of what would happen if Turnbull fell under a bus — and their leader is insisting on playing in the traffic. Joe Hockey is another Sydney moderate who might appeal to Sunrise viewers but who has certain Beazleyian air about him, of a lovely bloke who doesn’t quite cut it — and he’d also need to seriously tone down the bellowing in Parliament.

Hockey was also supposed to be the next generation, who would come into their own after the next election had been fought and lost and Malcolm Turnbull had gone back to printing money in the private sector or running for UN Secretary-General or something. The Liberals would need an expendable leader whose loss at the next election, and perhaps a purgatorial 12 months beyond, would allow another, longer-term leader to emerge. Julie Bishop is damaged goods, and Brendan Nelson is leaving. That leaves Andrew Robb, whose éminence grise act would be a stark and perhaps welcome contrast to Turnbull’s flamboyance. Robb’s substance and demeanour makes him the exact opposite of Hockey, and he has a pretty formidable brain as well. The climate sceptics in the party would also be more relaxed with him.

There’s also a relatively young Melbourne bloke with a good CV, but he’s likely to get a better offer from the Government at some point in the next 12 months. You can bet Julia Gillard and Peter Costello discussed more than the footy on the plane to Israel.