ALP equal love campaigners are confident of extracting significant “bleed” from the party’s Right on gay marriage at next week’s national conference, with just 20 defectors required to change Labor’s official platform and by implication federal law.

Crikey understands that the numbers on the issue have been worked feverishly over the weekend to corral the required 201 delegates needed to enact the historic change and end discrimination.

While the Left is expected to vote broadly as a bloc, individual delegates from the Right are being directly pressed to flush out their true position. The majority of the Australian public support same-s-x unions and Prime Minister Julia Gillard, who supports a self-defeating “conscience vote”, is primed for a fight.

Some of that support could come exclusively from Victoria. To get a sense how malleable the numbers are, the state’s 87 conference delegates (including Gillard) are divided into 40 Left and two non-aligned independents — all of whom would be expected to support the deletion of six key words from the Marriage Act.

On the Right are 21 so-called “Short-Cons”, seven aligned to the National Union of Workers and 17 from the socially-conservative Shop Assistants’ Union. While National Right convener and Victorian Senator David Feeney supports a conscience vote, there is significant potential for waverers within the NUW. And influential Australian Workers Union secretary Paul Howes has stumped for a free vote on the issue. The SDA, led nationally by the buttoned-down Joe de Bruyn, are not for turning.

One Left source told Crikey that the despite the PM “granting” the conscience vote — a move that would actually require a rule change to comply with the current platform — the change to wording remained “very much a live issue”. Media reports to date have declared the debate “doomed” in the wake of the PM’s intervention.

“This is not about left and right … support for gay marriage spans the factions,” they said, buoyed by yesterday’s national Left convergence at ANU in Canberra.

Insiders say the potential for mass defections is very real because the Right have to date framed their objections and initiatives in negative terms.

Nationally the Right has a slim majority — just 218 of 400 delegates. It has the numbers at the state level in Victoria, NSW and Queensland but not in Western Australia and Tasmania. In South Australia it maintains notional control, despite state secretary Kyam Maher hailing from the Left.

The Left’s self confidence has ballooned in recent weeks, with caucus chair and Victorian Senator Gavin Marshall penning two swingeing Fairfax op-eds on same-s-x unions and uranium exports.

Other issues on the table with some potential for traction include anti-dumping, changes to trade rules, industrial relations and domestic procurement. Live exports will also jostle for attention among the less contentions proposals on the environment and climate change.

As the official conference agenda makes clear, the main dose of colour and movement is expected to come on Saturday afternoon when debates fire up on the party’s constitution and rules.

The Left say the advocacy of the direct-election of national conference delegates, as recommended in the Bracks/Carr/Faulkner review report, would prevent the manipulation of the current college system. Despite dissent from United Voice, union influence would in fact be maintained. In the case of Victoria, the trade union half of state conference would continue to elect delegates, with senior Left sources maintaining this morning that the “critical issues of disaffection” would be addressed by the change.

Pitt Street’s Zilver Chinese Restaurant is shaping as a Left discussion hub. The famous dim sim menu is a prime attraction for activists, who’ve also acknowledged the cortex-stimulating qualities of the wok-tossed snake beans with oyster sauce.

And next Thursday’s “Rainbow Labor” fringe program kick off at the Belvedere Hotel is expected to raise apparatchik pulses as delegates raid closets to attend in full or partial drag.