ALI MOORE, PRESENTER: Tony Abbott's targeted a coal-mining electorate in Labor's heartland on the first day after the official unveiling of the carbon tax.

The move's aimed at convincing uneasy Labor MPs to help him defeat the tax, but tonight a group of Government backbenchers from mining seats are standing firm behind the Prime Minister.

They've issued a statement expressing full support for the controversial carbon plan, part of a political struggle that's assuming all the proportions of an election campaign.

Here's our political correspondent Tom Iggulden in Canberra.

JULIA GILLARD, PRIME MINISTER: Effectively, the starter's gun has gone off.

TOM IGGULDEN, REPORTER: The Prime Minister's got a year to make her unpopular carbon tax a reality.

Today her campaign machine swung into action in suburban Sydney.

Once inside, the biscuits were waiting; so was the media. And a made-for-TV family chat.

There wasn't much chance of an upset.

VOTER: I mean, I suppose I grew up in a Labor family, but that hasn't - that doesn't mean I need to vote that way.

TOM IGGULDEN: At the local shopping centre, an unscripted vote of support.

MAN: Julia! Julia! Good on you for the carbon tax. Well done with the carbon tax.

JULIA GILLARD: Thank you!

TOM IGGULDEN: Her main selling point's income tax cuts to offset increased prices caused by the carbon tax. Four million low income earners will be overcompensated.

Middle income earners get a smaller tax cut.

JULIA GILLARD: Around six million households will come out effectively square.

TOM IGGULDEN: For the rest, family budgets will take a hit, but the Prime Minister says they can afford it.

JULIA GILLARD: That's what it's all about. It's all about taking pollution out of our atmosphere because that is driving global warming, dangerous global warming.

TONY ABBOTT, OPPOSITION LEADER: This is an attack on aspiration. This is an attack on the aspirational classes of our country.

TOM IGGULDEN: Tony Abbott's media strategy's been the same for months. Today he was back in a coal mine in a Labor electorate.

TONY ABBOTT: I know many of you guys probably in the past have not thought all that much of the Coalition.

TOM IGGULDEN: He's hoping to change that through his pledge to destroy the carbon tax.

TONY ABBOTT: I mean, I have dedicated my political life, whatever's left of it, to stoping this carbon tax.

BARNABY JOYCE, NATIONALS SENATOR: You know the Greens want to close down all coal mines? OK. That's fair dinkum, you've seen it, they've said it. That means nobody in this room's got a job.

TOM IGGULDEN: The emissions-intensive steel industry's also in Labor heartland and the Government wants a support package for it.

BOB BROWN, GREENS LEADER: Difficult situation for the Greens, because the steel industry's not been, um, one of our biggest supporters.

TOM IGGULDEN: But the Greens Leader's indicating he might support the package anyway.

BOB BROWN: And I'm saying this to Tony Abbott: if you're going to let down that part of your own constituency, I'll go to the steel industry, I'll go Whyalla, I'll go to Wollongong, I'll go to meet the workers in the steel industry.

TONY ABBOTT: Let's put the boot on the other foot: will Julia Gillard be going to Whyalla? Will Julia Gillard be going to Port Kembla? I'll tell you where she'll be going. She'll be going to university campuses, that's where she'll be going.

TOM IGGULDEN: But Wayne Swan chose a different location.

WAYNE SWAN, TREASURER: Fired the starter's gun on getting the investment into renewable energy so we can develop the solar, the wind, geothermal energy ...

TOM IGGULDEN: The Treasurer's gone back on previous statements that the carbon tax would be revenue neutral.

WAYNE SWAN: There are upfront costs, but through the surplus years there's a minor pull on the surplus.

Joe HOCKEY, SHADOW TREASURER: This man is not fit to be the Treasurer! He can't count!

TOM IGGULDEN: That one got the crowd baying for more.

AUDIENCE MEMBER: What is the Coalition going to do to try and stop the people of Australia taking up arms against this government?

Joe HOCKEY: I can perfectly understand your anger, but we are a peace-loving nation.

TOM IGGULDEN: And no day of campaigning would be complete without a gaffe, this one from one of the government's better performers.

PENNY WONG, FINANCE MINISTER: So that's the answer.

ABC RADIO COMPERE: OK, how much will you raise?

PENNY WONG: I think it's about $18 billion from memory, over the forwards.

CHRISTOPHER PYNE, LIBERALS: Are you sure it's not $21 billion?

PENNY WONG: 21. He might be right.

CHRISTOPHER PYNE: It's $21 billion, John. I'm not the Finance Minister, but ...

ABC RADIO COMPERE: OK.

PENNY WONG: The net hit ...

CHRISTOPHER PYNE: ... I read the document.

TOM IGGULDEN: It's actually closer to $25 billion, but who's counting? This battle-to-the-death debate will come down to whether or not voters will be convinced that the Government's plan will clean up the atmosphere without costing them their job or a significant slice of their income.

Tom Iggulden, Lateline.