Labor leader Bill Shorten was doing more than channelling Paul Keating in his hard-hitting budget reply speech on May 15 for which he received sustained applause from the public galleries.

He was relying directly on the former prime minister’s expertise – and, in some cases even, his words.

Fairfax Media has been told the speech, the most important single oration Mr Shorten has made as leader, was workshopped with a wide variety of senior labour movement figures including several of his frontbench colleagues, former ACTU secretary Bill Kelty and, most crucially, Mr Keating – who advised on the final version.

Mr Keating dominated politics from the mid-1980s to the mid-1990s, crashing his way to the prime ministership in 1991 before losing to John Howard in the 1996 landslide.

Insiders confirmed Mr Keating remains in regular contact with Mr Shorten, acknowledging the pair spoke before the seminal speech, which was then sent to Mr Keating for further input.

Sources said the speech was not given a major reworking but that Mr Keating had offered his thoughts and provided a couple of ”vintage Keating lines”.

Quizzed about the role of Mr Keating in the current political contest, senior opposition figures attempted to play down the extent of his involvement, keen to avoid the suggestion that Mr Shorten’s words could be seen to have been someone else’s.

They were perhaps also aware that while Mr Keating is a favourite among Labor loyalists, his standing with conservative voters is less favourable.

Mr Shorten’s budget reply speech was praised as a political document but criticised by the government for not containing substantive policy ideas or an alternative economic plan.

But what it lacked in detail, it more than made up for in rhetorical flourish, pleasing ALP supporters in the public galleries to such an extent that the speech was punctuated with frequent applause and received a standing ovation at the end.

The version of the speech originally circulated to media differed in some minor aspects from the one given in the House of Representatives, which took on a more rousing tone, finishing with the feisty challenge: ”If you want an election, try us; if you think that Labor is too weak, bring it on.”

So concerned was the government at its favourable reception that the Leader of the House, Christopher Pyne, gestured to the Speaker, Bronwyn Bishop, instructing her to rise to her feet, thus bringing the applause to an end.