Discussion of Australian politics tends to be leadership-centred. So it came as no surprise when the media focused on two aspects of John Howard’s most recent entry into the political debate.

Namely, Howard’s reflections, as the second longest serving prime minister in Australian history, on politics, with particular reference to the government he led between March 1996 and November 2007; and Howard’s opinion on how the Liberal Party rank and file should respond to Tony Abbott’s replacement by Malcolm Turnbull as prime minister.

Yet Howard’s most significant contribution to the contemporary political debate occurred when interviewed by Leigh Sales on ABC television’s 7.30 on March 1.

Asked about the Senate reforms, which were considered in the parliament this week, the former prime minister replied that he understood the frustration of the public over the Australian Motoring Enthusiast Party winning a Senate seat in Victoria because of “preference whispering”.

Howard then added: “But people shouldn’t lose sight of the fact that the principal beneficiary of these changes is probably the Australian Greens and that is why the Australian Greens are so strongly in favour. So I hope this doesn’t presage some kind of understanding about preferences in the House of Representatives election between the Coalition and the Greens.”

It is understandable why the Abbott government and now the Turnbull government became frustrated about the Senate, which has blocked or defeated so much Coalition legislation in recent years.

Yet the prime driver of this outcome turns on the attitude of Labor, the Greens and Nick Xenophon in the Senate. The Greens and Xenophon supported the Turnbull government’s Senate voting reforms — so clearly neither Greens leader Richard Di Natale nor Xenophon is worried about these electoral changes.

The essential problem with the current Senate voting turns on decisions enacted by Bob Hawke’s Labor government in 1984, which received the support of the Nationals — but not the Liberal Party. Labor and the Nationals at the time saw advantages in increasing the number of seats in the House of Representatives.

Under the Constitution’s nexus provisions, this required that the number of senators also be increased. In the event, the senators elected from each state at each election increased from five to six.

The problem for Labor and Coalition governments since then is that it is easier for a government to win three out of five Senate seats than it is to win four out of six. Howard achieved a Senate majority in his final years, but this is unlikely to be repeated in the short to medium term.

This reality remains, irrespective of the impact of preference whispering — that is, trading preferences between minor parties to take advantage of the fact a valid vote could be cast by placing the number 1 above the line in the Senate ticket.

Despite the Coalition’s frustration, it is not clear that the current changes will resolve the impasse in the Senate — while Labor, the Greens and Xenophon vote down legislation along with a number of micro-parties and independents.

At the 2013 Senate election, the micro-parties scored relatively well. The Palmer United Party got 12 per cent of the primary vote in Western Australia, 9.6 per cent in Queensland and 6 per cent in Tasmania. With the quota at about 14 per cent, this vote saw the election of Dio Wang, Glenn Lazarus and Jacqui Lambie, respectively.

Only Family First in South Australia (3.5 per cent) and the Australian Motoring Enthusiast Party in Victoria (0.5 per cent) won Senate seats on very low votes.

But senators Bob Day and Ricky Muir are not the Coalition’s main problems. It’s true that Muir denied the Liberal Party a Senate seat in Victoria but Day prevailed over the Xenophon group, which consistently has voted against the government.

It’s not clear that the logjam in the Senate will be resolved by changing the voting system, irrespective of whether the next election is a double dissolution (on July 2) or a normal election for the House of Representatives and half the Senate (possibly in mid to late October). The Coalition may achieve little for possibly having enshrined the Greens as Australia’s only significant minor party.

Then there is the question of preferences. In 2010, Helen Kroger, a senator at the time, led the drive in Victoria for the Liberal Party to put Labor ahead of the Greens on how-to-vote cards in the Victorian state election. She was supported by Michael Kroger, currently president of the Liberal Party in Victoria. It is believed that this strategy helped the Liberals defeat Labor.

Now Kroger seems to have changed his position. On Sky News last week, he declared that the Greens, under Di Natale, are “not the nutters they used to be”.

But the Greens’ parliamentary team still includes left activists such as Adam Bandt, Scott Ludlam, Lee Rhiannon and Sarah Hanson-Young. Moreover, on the ABC’sLateline recently Di Natale described the Coalition government as “one of the worst administrations in the nation’s history”.

Abbott is one of the Liberal Party’s fiercest political warriors. Yet he acknowledged the support his government received from Labor leader Bill Shorten on defence and national security issues.

Any decision by the Liberals to preference the Greens ahead of Labor in the traditionally safe ALP Melbourne-based seats of Batman and Wills could lead to the defeat of leading Labor right-wing operatives David Feeney and Peter Khalil. This would not make any sense from a national security point of view.

Moreover, it is likely that many Greens voters would decline any advice from party headquarters to honour a deal to preference the Liberals ahead of Labor in seats such as Higgins and Kooyong, held by Kelly O’Dwyer and Josh Frydenberg, respectively. In other words, the Liberal Party could surrender the political high ground for little, if any, benefit.

Robert Menzies and Howard are the Liberal Party’s two most successful leaders. Both understood the need to proclaim a consistent position and not to send out conflicting messages to supporters.

There is no long-term benefit in the Liberal Party flirting with the Greens, Australia’s only party of the hard-Left. The likes of Kroger would be wise to fellow Howard’s advice.