Tony Abbott's budget attack is shamelessly contradictory. He slams the $2 billion saving from family benefits as ''class warfare'' that will hit ''struggling families'', but he is also blaming the government for looming interest rate rises because he says it is spending too much.

And he has no intention of repeating the mistake he made during the flood levy debate in January of making himself the issue by nominating alternative budget cuts to make up for the savings measures he decides to oppose. Instead he is simply pointing to the $50 billion in savings the Coalition lined up to pay for its election promises, even though the Treasury and Finance departments said between $7 and $11 billion of them did not exist.

Since the last election, at least another $6 billion of those savings have either been implemented by the government or redirected to other things, which might be a partial vindication of the Coalition's savings list but still leaves it short.

For the Coalition's strategy, none of this matters. Its budget response is not about policy detail, it's about furthering the ''Labor is out of touch on cost of living'' attack. If the assault can also be linked to the carbon tax or the asylum seeker issue, better still.

For those still interested in the detail, the budget's savings from family payments are actually achieved by freezing the income threshold for eligibility at $150,000, rather than increasing it in line with inflation.

The Coalition says the 40,000 families likely to slide out of eligibility as their incomes rise above $150,000 aren't rich. Wayne Swan agrees, but says the spending has to be sustainable.

The real question is whether families earning more than $150,000 still need help from the government and whether the nation can afford to pay it.

Leaders' arguments tied up in knots

to underscore the mad monk's cynical hypocrisy .....

Anyone would think the budget had frozen the income limits for getting family tax benefits at $150,000.

Talkback radio was alive with calls about it the day after the budget. Was a family income of $150,000 high or typical?

The shadow treasurer, Joe Hockey, thought it was typical.

"One hundred and fifty thousand a year for a family is certainly not rich Australia, it is very much middle Australia," he told the ABC. "Besides, I want people to aspire to earn $150,000 or more."

The budget documents themselves say that for the next two years the cutoff for getting family tax benefit B, paid parental leave and dependency tax rebates will be frozen at $150,000. That's $150,000 of personal, rather than family income - anything but typical.

The cutoff for receiving the baby bonus will be frozen at $150,000 of family income and the cutoff for family tax benefit A will be frozen at $94,316 of family income, increased by $3796 for each additional child after the first.

What the budget doesn't make clear - but should - is that these cutoffs are already frozen.

Labor introduced the $150,000 ceilings in 2008. Before that, family tax benefit B and other payments could go to the families of millionaires.

In its 2009 budget it froze indexation of those benefits and also for family tax benefit A for three years.

Since then anyone whose income has sailed through the ceiling has lost the benefit.

This budget extends the freeze for a further two years.

Budget 2011 | $150,000 freeze is nothing new