Shorten goads PM over NAB rate rise

Labor leader Bill Shorten has launched strong criticism of the National Australia Bank's decision to hike its standard variable mortgage rate.

NAB lifted the rate by 0.07 percentage points for owner-occupiers hours after the US Federal Reserve increased its key interest rate.

In an early morning television interview, Prime Minister Malcolm Turnbull said the rise was certainly not welcome.

"But as you know, the banks obviously have to manage their own affairs, and they have funding costs," he told the Network Seven on Friday.

In a later interview, Mr Turnbull wouldn't repeat his claim, saying it was up to the banks to justify their decisions.

"If they don't explain it then NAB customers will go somewhere else and I'd encourage them to do so," he told 3AW's Neil Mitchell.

Mr Turnbull talked up his decision to haul banking executives before a House of Representatives committee to explain their practices.

But Mr Shorten, who backs a royal commission into the sector, wanted him to go further.

"Just how out of touch is Malcolm - don't blame me, I'm only the prime minister, - Turnbull have to be?" he told reporters in Canberra.

"When asked about the NAB increasing mortgage rates, Mr Turnbull just doesn't have an opinion.

"I do. I think when the Reserve Bank's keeping the official interest rates at record lows, I don't like the banks increasing the mortgages of every Australian."

Mr Shorten said instead of proposing a corporate tax cut for the banks, he would give them a royal commission.

Labor frontbencher Anthony Albanese said the NAB rise was another example of the banks being out of touch.

Cabinet minister Christopher Pyne hadn't seen the decision but urged disgruntled NAB customers to shop around.

"It is not nearly as hard to move banks as people think it is," he said.

"I have done it a couple of times and is it not that difficult."

The lender's standard variable rate for owner-occupiers will rise to 5.32 per cent on March 24, and its investor rate will rise 0.25 percentage points to 5.8 per cent.