Brisbane Lord Mayor Graham Quirk.

Brisbane Lord Mayor Graham Quirk has been asked about a potential rates rise tripling in this year's budget.

Lord Mayor Graham Quirk has refused to address a prediction this year's rates increase could be three times higher than last year.

The Queensland Treasury Corporation report into Brisbane's finances, published in September 2011, forecasts rates increases of 5.7 per cent for 2012-13 and 5 per cent each year until 2021.

Cr Quirk handed down an increase of 1.79 per cent last year after the January 2011 floods.

But he and his finance committee spokesman Cr Adrian Schrinner are under greater financial pressure this year as a result of Legacy Way tunnel construction costs and flood recovery bills.

When asked about the tightening financial pressure at his election campaign launch yesterday Cr Quirk said he would comment on the make-up of Brisbane City Council's budget at a later date.

"I will be making statements about rates at another time, but I think we can say today that I delivered on a very, very small rate increase in the budget last year," he said.

"It was half the inflation rate - 1.79 per cent - for residents and business alike."

Cr Quirk would not elaborate on the make-up of the 2012-13 budget, when asked again.

"I will be making announcement on rates when I get a little closer to the election," he said.

The low 1.79 per cent rates increase handed down on June 8 last year added around $21 a year, however many suburbs paid much higher rates.

But if Brisbane City Council adopts the QTC's recommendations, this year's basic rates increase must triple last year's Council rates rise and add between $60 and $65 a year.

In now-Premier Campbell Newman's last term as lord mayor (2010-2011) the average rates increase was 5.04 per cent and added on average about $60 to the average rates bill.

Queensland Treasury Corporation is satisfied Brisbane City Council has a strong "revenue base" and can afford the debt.

It notes in the same report that "net debt" will reduce after the tunnel is finished.

But Brisbane still has some payments to make on the $400 million flood recovery damages it received after the January 2011 floods.

Also Brisbane City Council's gross debt level almost doubles - from $1.186 billion in 2011-12 to $2.389 billion in 2014-15 - mainly to pay for the $1.7 billion Legacy Way tunnel from Toowong to Bowen Hills.

Labor's mayoral candidate Ray Smith said the Legacy Way tunnel was predicted to run at a loss of an average $52 million for each of the first five years after 2015.

Mr Smith said Graham Quirk's budget last year was delivered as "an election budget."

"But in years to come, he has budgeted for five per cent rates rises," he said.

"That's also in their budget. That was he has budgeted for; that's not me making it up."

Mr Smith also questioned the level of the rates cap - now set at 7.5 per cent - which lets residents in some suburbs pay higher rates before a rates "ceiling" come into effect.

"So while he publicised that - across the board - he has an average rates rise that was kept low, then there places like Enoggera and Mitchelton and Keperra and Geebung that did not feel that happen."

"They had rates rises almost double inflation."

Mr Smith said Cr Quirk was under "extreme pressure" to keep this year's Council budget increase to the Brisbane inflation figure of 3 per cent.

"Last year's budget was an election budget; this year's - if he is elected - won't be as friendly."

He acknowledged he faced the same pressures but said his priorities were different.

Deputy Mayor Adrian Schrinner said the forecast from Queensland Treaury Corporation had no bearing on council's decision on rates.

He cited an instance when the QTC forecast that council would raise rates above the CPI in 2011-12, yet Lord Mayor Graham Quirk handed down one of the lowest rates increases in 35 years at just 1.79 per cent - less than half the Brisbane inflation rate (3.6 per cent).