The sting will be in a fresh round of increases to rates on homeowners, with rates rising an average of 10 per cent a year over the past two years and another 10 per cent increase on the cards this year.

In 2012, the government began an ambitious plan to phase out stamp duty and insurance taxes, replacing the revenue with higher rates. Insurance duty is going the quickest, due to be scrapped altogether by the 2016 budget. Stamp duty is being phased out much more slowly, over 20 years. To date, the government has reserved its biggest cuts to stamp duty for specific groups: first home buyers and – last year – over-60s moving to downsize.

Chief Minister Andrew Barr told the Assembly this month that every home buyer would pay less in stamp duty after his June budget. He did not say by how much, but if he sticks to the plan set out in the past two budgets the saving looks to be $1200 compared with the amount you would pay today. Any cuts to stamp duty would take effect when the budget is brought down.

For a house worth $500,000, the buyer would pay $14,600 – a cut of $5900 since the tax changes began three years ago.

For a house worth $750,000, the buyer would pay $27,100 in stamp duty – a cut of $7775 over three years.

And for a house worth $1 million, the stamp duty would be $43,350 – a cut of $5900 over three years.

These figures assume the government sticks to the figures set out in previous budgets, but that is not guaranteed.

The government has not set out a plan for rates increases to make up for the loss of stamp duty revenue. But modelling released in 2013 suggested rates could rise 10 per cent a year in the early years, including 2015-16, then perhaps eight per cent a year in the following years over the 20-year switch.

The government has not confirmed that scenario, and the only indication from last year's budget is the overall amount it expects the government to make from rates in 2015-16. The figures in last year's forward estimates suggest an overall increase of $45 million in rates in the coming year, or about 12 per cent, including rates from the increase in the overall number of properties.

After last year's budget, Canberra homeowners paid an average $1684 in homeowner rates. If the government opts for a similar increase this year, the average rates bill would climb to about $1850 from July. People's individual rates depend also on changes in house values in each suburb.

Mr Barr has promised a budget that will seek to stimulate Canberra's economy and will be focused on suburban renewal, with promises for each of the town centres. One major project is the new public hospital at the University of Canberra, to which the government has not attached a price tag. Another is the $783-million tram line, whose more significant impact on the budget will come later when trams beginning operating and the government begins paying an annual fee to the private operator. The government has also indicated it is set to pay a lump sum of perhaps half the project debt to the private operator once construction is finished or soon after.

The biggest hit to the budget since last year is the decision to fund a buyback and demolition of 1021 asbestos-contaminated homes, costing up to $1 billion. That has seen this year's deficit plunge to a forecast record-setting $770 million. But Mr Barr has insisted that the Mr Fluffy impact will not result in a major change in fiscal policy settings, insisting "there's no need to panic".

He told the Assembly this month that the tax cuts would continue.

"Our forthcoming budget will continue to lower conveyance duty and insurance taxes," he said. "Every homebuyer will see a reduction in their stamp duty bill, making buying a home more affordable for Canberrans. Insurance taxes will again be cut, as part of our approach to abolishing this tax once and for all from the territory's statute books."