As the battle for federal seat of Melbourne reaches boiling point, Greens candidate Adam Bandt has questioned Cath Bowtell’s progressive credentials in a last ditch effort to woo traditional Labor voters. And Bowtell has secretly marshalled dumped PM Kevin Rudd to bend the ear of locals in a campaign blitz away from the prying eyes of the media.

Electors in the knife-edge inner-city seat returned home last night to find this direct mail plea claiming Bandt would be “a stronger representative and independent voice for Melbourne than someone forced to conform to a Labor Party or factional line.” An accompanying flyer courts the teetering lefties the Greens desperately need to keep the ALP’s vote under 50% so Bandt can leapfrog Bowtell on Liberal preferences. It massages fears of change, claiming that “if…Greens preferences are distributed your vote goes straight to Labor as a full value vote.”

But just as voters were mulling that scenario, a select few were confronted by the presence of Rudd, fresh off the plane from Queensland, to talk about the Greens’ complicity in dumping all things ETS. An adviser confirmed to Crikey this morning that Labor’s ghost was consulting closely with community leaders alongside Bowtell.

Previously, the Greens had focused on their own progressive boasts, while Labor, which has held the seat since 1904, has built its pitch around the idea that Bowtell, an “activist woman” schooled in hand to hand combat at the ACTU, would be a powerful force for change within the federal ALP caucus. Bowtell has spoken out on same s-x marriage and has promised to agitate Penny Wong-style to put a price on carbon.

But Bandt’s supporters counter that as the first lower house Green elected at a general election, his mere presence would send a message to Labor to listen to the left to avoid losing other fiefdoms such as Sydney and Grayndler in 2013. Assuming a slim Labor majority, Bandt would have to rely for a large part on his symbolic appeal. In the event of a hung parliament, he could emerge as a kingmaker in league with independents in what Bob Brown called yesterday a “rolled gold opportunity”.

However, a Labor strategist told Crikey this morning a hung parliament “risked the possibility of Tony Abbott becoming PM in order to sent a message to the government.” Convention dictates that the leader of the party with the most seats will be anointed Prime Minister, and a Bandt victory could be crucial in tipping the balance in favour of the coalition, the strategist said.

In a further twist, some Greens supporters have suggested Labor campaigners will be casting a first preference vote for Liberal candidate Simon Olsen to increase the likelihood Bandt will come third on primary votes. But claims Bandt’s preferences would “go straight to Labor” relies on the assumption that the Greens would finish behind the Liberals, a prospect dismissed by insiders this morning as highly unlikely.

Third party endorsements have also started to get messy. On Monday, Bowtell sent a direct mail entreaty in which the popular director of the Sudanese Lost Boys Association of Australia, Akoc Manheim, backed Lindsay Tanner’s record in working with recent arrivals and Bowtell’s plans to continue his work.

“I believe Cath Bowtell can build on Lindsay Tanner’s work,” Manheim wrote. “She has the credentials, and she would care the way Lindsay Tanner did.”

The letter prompted a friendly phone call from Bandt to enquire whether a previous pledge to remain non-partisan in the fight was still current. Bandt told Crikey that a journalist from The Age, Farrah Tomazin, had contacted his office to find a local public housing resident to provide comment on this July 29 story on a Greens pledge to reduce cost of living pressures on public housing tenants. But Manheim declined to be quoted and an alternative was sought.

On Tuesday night at Bowtell’s official fundraiser at the San Remo Ballroom, around 10 Sudanese and 20 Somalis officially farewelled Tanner and welcomed Bowtell as the new candidate. But Bandt has also maintained some links with African-Australians, providing legal advice in his role at Slater and Gordon and as an advocate in the lead-up to the 2007 poll when Kevin Andrews linked Australia’s refugee intake to a fake crime wave.

Meanwhile, Labor continues to protest over another third-party endorsement provided by North Melbourne resident Alison Parkes. In it, Parkes claims she had seen the light after previously handing out how to vote cards for Tanner, a claim repeated in this 7:30 Report story in May. However, Tanner loyalists say that they can’t remember Parkes’ presence on the campaign trail.

Another former Labor voter, activist Doug Evans, is a core member of the Yarra Climate Action Now group.

And as Crikey revealed last week, a number of other turncoats, who have appeared on Greens posters under the headline “this time I’m voting Greens”, are actually key volunteers or related to party powerbrokers.

Tensions between the warring camps have also risen following a front-page story in yesterday’s Age outlining the full extent of the Electrical Trades Union’s support for Bandt and the Greens’ Victorian Senate campaign. ETU chief Dean Mighell had previously told other outlets, including Crikey and The Australian, that his total donation to the Greens in Victoria stood at $120,000, rather than the marquee $325,000 figure quoted yesterday. As Crikey reported last week, Labor has also been the beneficiary of substantial union cash and in-kind support.

The mood for change in Melbourne is difficult to gauge. While both the Greens and Labor conducted extensive focus group research in the campaign’s early days, both have been running blind without the benefits of private polling. This afternoon, Greens leader Bob Brown will mount a flatbed truck in Fitzroy to address a shrieking posse of supporters brandishing party propaganda before launching a “blitz” of Melbourne’s inner suburbs.