Treasurer Jim Chalmers stood in front of 600 guests at his post-budget speech in Parliament House yesterday and repeated a big budget fib.

This is not semantics or a small rounding error. The discrepancy is significant – worth tens and tens of billions of dollars in spending.

Chalmers claims he has successfully curtailed the growth in real (inflation adjusted) government spending to 1.4 per cent annually over six years. If he was actually achieving this spending restraint, Chalmers would deserve high praise.

This writer would be at the front of the line to shake the treasurer’s hand and would dedicate column inches to such fiscal discipline.

But the evidence of the Albanese government’s spending performance is very different, according to its own budget document. Real government payments (even discounting for the high inflation rate) are on track to be up 4.5 per cent in the year ending June 30.

Next year, real spending growth is forecast to be 3.6 per cent, before any election goodies and further ‘‘unavoidable’’ spending surprises. Labor’s track record so far is about triple the 1.4 per cent claim.

Chalmers uses two routes to get to his claimed 1.4 per cent average over six years.

First, he includes minus 4.9 per cent in 2022-23 – a cut in real spending due to the unwind of COVID-19 stimulus in the previous year.

Second, he is counting on projected weaker spending growth beyond 2025. This is unrealistic and will never be achieved because it allows for no future new spending, including for elections.

The budget projects real spending growth of 1.8 per cent in 2025-26, 0.8 per cent in 2026-27 and 2.4 per cent in 2027-28.

I called the treasurer out on this at a pre-budget press conference last week, and was prepared to let it slide if he stopped boasting about it.

But yesterday he brazenly stood up in the National Press Club speech and repeated it to a big, important crowd, saying Labor was ‘‘restricting real spending growth to an average of 1.4 per cent, compared to 4.1 per cent under our opponents’’.

The former Coalition government’s spending included $300 billion of pandemic stimulus. Labor supported this, and in some cases advocated for additional outlays.

Stripping that stimulus out, the Coalition’s pre-COVID-19 spending averaged 2.1 per cent real growth over seven years, according to economist Chris Richardson, similar to the 2 per cent real spending growth cap Chalmers’ old boss, former treasurer Wayne Swan, admirably set as one of his budget rules, before breaching it.

Chalmers has imposed no such spending rule.

As an aside, Chalmers is right that shadow treasurer Angus Taylor is being deceitful by criticising tens of billions of dollars of extra spending from the automatic indexation of welfare payments and pensions. This would occur under both sides of politics. Indexation is not a real spending increase.

Nevertheless, federal spending as a share of the economy is forecast to hit 26.6 per cent of GDP in 2025-26. Take out the pandemic years and this is the highest since the mid-1980s.

It’s higher than the Rudd government stimulus during the 2008-09 global financial crisis, and it’s due largely to cost blowouts on the National Disability Insurance Scheme and aged care under the former Coalition government and now Labor.

The only government that achieved sustained spending restraint was Labor’s Bob Hawke and Paul Keating in the late 1980s – three years of real spending going backwards by about $100 billion a year in today’s dollars.

Until there is any evidence of Chalmers and Finance Minister Katy Gallagher delivering on the claimed low spending growth, the treasurer should stop repeating the disingenuous claim.