As MPs and senators cram together in the House of Representatives today for the first of three parliamentary addresses by foreign leaders — providing a much-needed revenue boost to airlines — non-Labor politicians will have much to ruminate on.

Things continue to go poorly for the government. The Shirking of the Shirt-front and the Obama-Xi climate agreement were only the most prominent features of a rough week. Most voters would have missed the more substantial news, that Treasurer Joe Hockey admitted the budget situation was deteriorating because of revenue write-downs, a problem we were assured had been solved by a more conservative approach to budgeting by Hockey and Treasury’s own, in-house analysis of why it repeatedly overstated revenue under Wayne Swan.

Hockey, who less than two years ago boldly declared he would deliver surpluses immediately after he became Treasurer and forever after, says he won’t be chasing offsetting savings in the Mid-Year Economic and Fiscal Outlook , which is the right call in macroeconomic terms but will leave the deficit to blow out yet again. Turns out surpluses aren’t in the Coalition’s DNA quite so much after all. Remember, the Hockey strategy was to worst-case the budget settings and pile as much spending as he could into last December’s MYEFO in the expectation growth would lift revenue beyond forecasts and demonstrate the intrinsic fiscal brilliance of the conservative side of politics. Now, he’ll have to explain to voters why the budget deficit has worsened yet again. Will he try to blame Labor again, more than a third of the way into the government’s term? As Prime Minister Tony Abbott might say, you bet you are — you bet I am. Still, not a good look on what is supposed to be the government’s trump card, economic management.

It’s economics, of course, that the government wants the G20 to focus on, which is why Abbott doesn’t want climate change mentioned — a changing climate that significantly alters water resource allocation, agricultural production, flood and storm damage, drought and fire damage, increases mortality among the elderly and erases entire low-lying states to create millions of refugees being a non-economic issue. In practice, any economic benefits to Australia from the G20 meeting — it’s not a talkfest, Abbott insists — are likely to be smaller than the cost to Brisbane businesses of being locked up and occupied for days. The much-vaunted 2% economic growth targeted is fanciful (as independent analysts have pointed out), especially when the eurozone is persisting with the Germany-led austerity policies that have now given the continent a longer depression than the 1930s. If the grouping delivers real progress on tax avoidance, that will yield long-term benefits for future treasurers, but benefits that will have to be earned through appropriate regulation and resourcing of the Tax Office.

“We thus look forward to Clive’s theories about which malign cabal has turned Lambie’s head and lured her from his grasp.”

Speaking of tax dodgers, Glencore rounded off the government’s bad week with its announcement this morning it was shutting down production of all of its coal operations for three weeks. Coming on top of the Xi-Obama agreement and the expected weakening of China’s thermal coal consumption, Glencore’s decision — motivated by huge oversupply and depressed coal prices — is another blow for the self-appointed King Coal, Tony Abbott, who has repeatedly declared his passion for the stuff while undermining investment in renewables.

There’s some better news, however, with Palmer United Party Senator Jacqui Lambie’s seemingly inevitable split from Clive Palmer. You never needed a crystal ball to predict Lambie and Palmer were going to be a poor fit — a few seconds listening to Lambie was always enough to work out she would be trouble for whichever party she ended up with. Currently, it looks like she’ll struggle to reach six months as a PUP Senator before bailing out, following her chief of staff, the “much-travelled” (as they say of footy players) Rob Messenger.

That’s par for the course both with micro-parties suddenly gifted with some electoral success — as per Hitchhiker’s, they go to pieces so fast people get hit by the shrapnel — and life with Clive. Palmer falls out with people so often he needs a parachute, and the descent is often accompanied by conspiracy theories as to why an individual has proven unable to work with such an eminently reasonable gentleman as the mining magnate. We thus look forward to Clive’s theories about which malign cabal has turned Lambie’s head and lured her from his grasp.

Her looming liberation has been portrayed as a problem for the government, with a free agent Lambie, Senator for the great state of Truculence, promising to oppose everything unless she gets her way on Australian Defence Force pay, but it also represents an opportunity, if the government can find a way to resolve the pay dispute, to go around Palmer — although admittedly, Clive has been so accommodating of late that it’s hard to see how Lambie could go further in helping the government secure passage of its bills.

Meanwhile, the Greens are focused on the Victorian election, where both majors are preferencing against them, making the task of picking up lower house seats nigh impossible. But Victoria is — the unusual Western Australian Senate election this year aside — one of the Greens’ strongest states; indeed, with Bob Brown retired, it now rivals Tasmania for the strength of the Greens vote federally. And after a relatively poor 2013 performance, the Greens have got a little of their mojo back under Christine Milne, with that very strong WA performance from Scott Ludlam and consistent polling at around 10% nationally.

For Labor, well, no one’s really taking much notice despite the government’s and the News Corp prostatariat’s efforts to shift the focus onto Bill Shorten. With the government continuing to stumble, there’s not much need for the opposition to do more than watch.