Australia’s second-longest serving leader told The Standard that Dr Napthine was an engaging leader with a strong economic record.

“Denis Napthine has put Victoria in the best budget position out of any state in Australia,” Mr Howard said in an exclusive interview.

“The transformation that Victoria achieved in four years is remarkable. It’s a colossal achievement to go from a difficult budget position to a strong surplus that any state treasurer in Australia will give their eye teeth for.

“It’s also a trustworthy government. If one looks at all the objectives, the Napthine government has a stellar track record of economic management.”

As prime minister, Mr Howard came into regular contact with Dr Napthine when the latter served as Victoria’s opposition leader between 1999 and 2002. 

He admired Dr Napthine’s approach to power and said last year’s leadership switch from Mr Baillieu to the incumbent premier was a notably smooth transition, given how acrimonious internal politics can sometimes be.

“Denis Napthine didn’t seek to replace Ted Baillieu but once he became premier his performance has been impressive,” the former prime minister said.

“(Dr Napthine) strikes me as a strong but caring leader who is optimistic about the future of his state. He has a sunny disposition and I think it’s always good to have a leader who is optimistic and engages well with voters.”

Former prime minister Malcolm Fraser has also backed Dr Napthine and told The Standard in August that the state government “deserved a second term”.

Mr Howard echoed comments made by Mr Fraser earlier this year and said he was concerned about Opposition Leader Daniel Andrews’ links with controversial trade unions.

“The economic management displayed by Denis Napthine is a stark contrast to what has been presented by Labor,” Mr Howard said.

“The continued alliance between Mr Andrews and the CFMEU (Construction, Forestry, Mining and Energy Union) should be of concern to Victorian voters. It’s clearly bad news.”

Another former PM, Julia Gillard, has also been on the state election trail, acting as a keynote speaker at a fund-raiser for the Victorian Labor campaign hosted by cardboard magnate Jeanne Pratt this week.

Mr Howard returned to the limelight last week with a keynote address at the Remembrance Day service in Canberra. He has also released a book — The Menzies Era — covering the achievements of one of his predecessors, Sir Robert Menzies.