Ferguson 'joined the other side' on IR

Labor's current workplace relations spokesman is disappointed former minister Martin Ferguson has "joined the other side" and backed the coalition's industrial relations agenda.

But Brendan O'Connor isn't surprised his former frontbench colleague made the comments.

Mr Ferguson, now the chairman of an Australian Petroleum Production and Exploration Association advisory board, urged the coalition government in a speech on Friday to look at elements of the Fair Work Act, saying high labour costs and low productivity were an unsustainable mix.

Mr O'Connor said the former resources minister was putting the view of his employer.

"I'm very disappointed with his view but not entirely surprised," he told Sky News on Sunday.

"He has joined the other side - that's not a slight, that's not a conspiracy theory, it's the reality."

He couldn't recall Mr Ferguson ever expressing similar views, especially about the need for the Australian Building and Construction Commission's re-establishment, when he was a minister.

"I'm not suggesting his view's disingenuous but I would say he is wrong," Mr O'Connor said.

"That may well be his heartfelt view but in the end he's speaking publicly, he's not just making a private comment ... as a chair of that board of that employer group."

But fellow Labor MP Joel Fitzgibbon said Mr Ferguson had held strong views about productivity for a long time.

He rejected the notion Mr Ferguson was only saying these things because he'd joined big business.

"I think he's been putting these views privately and publicly for a long time," he told ABC TV.

"He wasn't talking about low paid workers. He was talking about ... those working in the trade exposed mining and petroleum type industries where international competitiveness is so important."

However, Mr Fitzgibbon said Labor believed there was sufficient flexibility within the Fair Work Act to allow employers and employees to join to drive up productivity.

Prime Minister Tony Abbott said it was good Mr Ferguson "has found his voice".

"I guess it's a pity that he didn't find his voice more vigorously when in government," he told Network Ten.

Mr Abbott rejected the former union leader's criticism that he was being too timid on industrial relations.

The prime minister pointed to the royal commission into the unions, and the government's legislation to restore the ABCC and overhaul the Fair Work Act.

"So quite a lot is happening, and at the moment Martin Ferguson's old comrades are making it almost impossible to get any of this legislation through the Senate," he said.