Labor elder Bob Hawke has written an open letter to voters calling on them at Saturday's federal election.
"While Bill's political opponents argue his trade union background is a liability for a future prime minister, I consider it an asset, as it was for me," the former Labor prime minister writes.
"It gives him the experience to achieve consensus with business, unions and community-based organisations for the challengers that lie ahead."
Former prime minister Bob Hawke has written a letter urging voters to back Bill Shorten on Saturday. Source: AAP
Mr Hawke was ACTU president before he entered parliament, while Mr Shorten was Victorian secretary of the Australian Workers Union.
Prime Minister Scott Morrison has been arguing that the Liberal/National coalition should be returned because a vote for Labor would lead to "union control of the government".
On the other side of politics, John Howard - who has been campaigning across the country for local candidates - told The West Australian a Shorten government would be more divisive than the Hawke government.
Labor leader Bill Shorten. Source: AAP
"Bob Hawke may have risen to greater heights in the union movement than Bill Shorten but Bob Hawke was far less beholden to the unions than Mr Shorten is," he said.
"There is no doubt the unions will be back in charge under Mr Shorten."
Mr Hawke, 89, said Mr Shorten's front bench is the best Labor team since the one he led in the 1980s and they were the only party offering stability.
"Over the past six years, the Liberals have had three leaders while Labor has had one, and three treasurers while Labor has had one shadow treasurer," Mr Hawke writes.
"As I said repeatedly when I was prime minister, if you can't govern yourselves, you can't govern the country."
Prime Minister Scott Morrison has been arguing that the Liberal/National coalition should be returned because a vote for Labor would lead to "union control". Source: AAP
It's Mr Hawke's second entry into the election debate. He joined forces with former treasurer - and foe - Paul Keating to endorse Labor's economic plan earlier in the campaign.
Mr Keating has been vocal since the Labor campaign launch, which included a stinging attack on Home Affairs Minister Peter Dutton.
On Tuesday, he urged voters in Dickson to put "a stake through his dark political heart".
