The Australian Council of Trade Unions has again pleaded with the Reserve Bank not to lift interest rates at its board meeting today.

The ACTU says a new poll shows three out of four working families are struggling to stay afloat financially.

The Essential Research poll of 1014 people also found the debt of 33 percent of Australians had increased in recent years, with two out of three - 68 percent - saying their large mortgages have gotten bigger.

Around 75 percent of working families said they were struggling to keep their heads above water.

ACTU president Sharan Burrow said the poll showed that working families could not afford another interest rate rise.

“This poll shows the vast majority of Australians think the banks are greedy and care more about profits than people," she said.

“The banks have been increasing their mortgage rates above the amount set by the Reserve Bank and there are now record numbers of Australians at risk of defaulting on their home loans. The banks need to understand they are part of our community and should act more responsibly in the way they treat people struggling to repay debts."

“This poll also shows that the legacy for working families of the former Liberal government is an unsustainable level of financial insecurity."