Opposition Leader Bill Shorten says Labor greats including former prime minister Paul Keating and union figure Bill Kelty helped write his first budget reply speech.

Labor MPs who doubted whether their leader’s communication style was cutting through were pleasantly surprised with Mr Shorten's first major address.

But it has been revealed Mr Shorten asked former prime minister Paul Keating for some help in scripting his lines.

"I'm a big fan of Paul's," Mr Shorten said.

"The budget reply speech was a statement of Labor values. I was very grateful for the great reception it had.

"I'm very grateful for the ongoing advice of many in my caucus and many former great Labor people, including Bill Kelty and Paul Keating.

"I think that Paul Keating was a great prime minister and one thing's for sure, when he was treasurer I think he was much better than Joe Hockey will ever be."

Liberal MP Ewen Jones has mocked the revelations, telling the ABC that Mr Keating probably wanted to begin the speech with "this was the budget reply we had to have".

"What a meeting," he said. "Two of the greatest Labor minds in a generation and some other guy."

Mr Jones said whatever input the two Labor giants had made to Mr Shorten's speech, it did not show.

"All those brains, a 33-minute speech and not one option put," he said.