The Abbott government has entered its final parliamentary sitting fortnight of the year hoping a re-alignment in the Senate and a worsening revenue picture might lead to a late breakthrough in the deadlocked legislature.

But hope is not being confused with belief despite billions of dollars of budget savings being stalled amid pale revenue from soft economic growth, weak company tax and capital gains receipts, and tumbling iron ore prices.

A tough day at the hands of a rejuvenated opposition, and fears of defeat in the Victorian state election this weekend, had the coalition backbench looking sullen and morally defeated on Monday.

Labor focused question after question on Prime Minister Tony Abbott's election-eve commitment that there would be no cuts to the ABC or SBS, among a raft of similar pledges involving health, education, and pensions.

"Did the Prime Minister say on the night before the election, September 6, 2013, on SBS television, did he actually say, "No cuts to the ABC or SBS."? Labor's Bill Shorten asked, again and again.

"I never said there would be special treatment for the ABC," Mr Abbott responded to derision from the opposition and near silence on his own side as MPs attended to mail or stared at mobile screens.

"Everyone knew there was going to be an efficiency dividend applied across government and effectively what we are doing to the ABC is applying an efficiency dividend to it."

"Was it you?" Labor MPs taunted, as Mr Abbott's own words about political trust were quoted back to him.

As Treasurer Joe Hockey prepares to unveil his crucial Mid-Year Economic and Fiscal Outlook snapshot of the budget and economy in mid-December, the government is struggling with low public support, and a record of legislative failure on key aspects of its budget plan.

While Julia Gillard's minority government lacked legitimacy and relied on the support of two country independents for its majority, the Abbott government's thumping lower house margin has not given it the parliamentary authority such dominance would suggest.

Instead, it finds itself beholden to a clutch of conservative populists and has proved unable or unwilling to navigate legislation through or hold it back until success if possible.

One senior MP insisted the Prime Minister was in a positive frame of mind, while counselling against panic.

According to the government, just seven of its bills have been "negatived" (successfully voted against) by the opposition and cross benches in calendar 2014 including a bill to scrap the Clean Energy Finance Corporation (twice) and another to scrap the Climate Change Authority.

Also rejected was the Clean Energy (Income Tax Rates) bill, the Fair Work (registered organisations) bill and a series of social security bills - the latter of which have been re-structured and then re-committed in a different form to secure $2.7 billion in savings.

According to the opposition however, a total of 23 government bills (albeit counted differently) have been repudiated in the Senate this year.

The government had proposed restoring a balanced budget in four years deleting the deficit by 2017-18 but that is looking increasingly unlikely with key savings measures yet to be legislated - causing the loss of months and potentially years of savings - and the weakening revenue situation.

However, the break-up of the 4-vote Palmer United Party bloc, after Tasmanian senator Jacqui Lambie made her separation official on Monday, and other manoeuvrings, offers some faint hope of progress.

For example, Liberal Democratic Party senator, David Leyonhjelm has begun constructing a majority to strike a compromise on the Renewable Energy Target.

He hopes to offer the government progress on its plan to trim the RET's impact, by removing the penalties on companies for failing to purchase sufficient green energy.

It is one of a range of possible issue-by-issue groupings that may become possible if the government drops an all-or-nothing mentality in favour of compromise and the pursuit of partial success.