Scott Morrison’s government is under pressure to introduce a new system for deciding whether to change part of the income test for pensioners.

The coalition is currently weighing up whether to lower deeming rates, which could leave some pensioners thousands of dollars better off.

Deeming rates are used to calculate how much some pensioners are earning on their financial investments.

The rates were last set in 2015 and are as high as 3.25 per cent, depending on individual circumstances.

Since then, the Reserve Bank of Australia has cut the official cash rate five times to a new record low of one per cent, meaning savings stashed in bank accounts are earning less interest.

Social Services Minister Anne Ruston has indicated the government will shortly make a decision on the rate.

“(I) have sought some pretty detailed advice which I’m considering and I’m consulting with my other cabinet colleagues,” she told ABC radio on Monday.

“We will be making our decision imminently.”

While 75 per cent of pensioners aren’t impacted by deeming rates, the minister acknowledged it was a crucial issue for the remaining 25 per cent.

Labor social services spokeswoman Linda Burney wants immediate action, arguing pensioners could be up to $3875 a year better off if the rate was brought in line with interest rates.

Council on the Ageing chief executive Ian Yates agrees the rates need to be adjusted but argues they should also be reviewed every six months against a pre-determined set of benchmarks.

That’s how the pension is indexed to account for inflation, he said.

“Why is it that this one component of the pension system, which is deeming rates, is not related to an objective basket of measures that gives us a benchmark to adjust it on?” Mr Yates told AAP.

“It would take the uncertainty for a part-pensioner out of what they’re going to earn.”

Centre Alliance MP Rebekha Sharkie said she wanted the deeming rates decided by an independent authority that also looks at whether the pension is keeping up with the cost of living.