Independent MP Andrew Wilkie says he and Senator Nick Xenophon will lodge a formal complaint over Channel Nine's airing of comments on poker machine laws.

The move came ahead of Sunday afternoon's NRL grand final, which featured big-screen advertisements labelling the pokies reforms un-Australian.

Channel Nine reportedly said there would be no editorialising during Sunday's television commentary, unlike last weekend when commentators Ray Warren and Phil Gould discussed Mr Wilkie's proposed mandatory pre-commitment reforms during the station's coverage of an NRL semi-final.

Mr Wilkie says it was passed off as commentary when it sounded more like political advertising.

He told Sky News a letter of complaint would be sent to the Australian Communications and Media Authority (ACMA) tomorrow.

He said while Channel Nine and the NRL were entitled to campaign against the changes, there were clear rules governing political advertising on TV.

"If someone is going to effectively make a political advertisement, then there are issues that it has to be identified as such and authorised," he said.

"People need to make quite clear what their interests are in this matter.

"When you have commentators who have clear links to rugby league clubs and hence a clear interest in the financial performance of those clubs, they should make that quite clear, otherwise they are at risk of deceiving their audience.

"In this case there is a prima facie case that Channel Nine and the commentators are in breach of the existing legislation."

'Un-Australian'

The Nine Network reportedly confirmed there would be no editorialising on gambling reform in Sunday's NRL grand final broadcast.

But News Limited said league legend Steve Mortimer would feature in big-screen advertisements to tell the 82,000-strong crowd that the reforms are un-Australian and will hurt the football code.

Finance minister Penny Wong says the Government will not bow to such pressure.

"I think we've got to keep focused, and [remember] what's important and what's right," she told Channel 10.

Mr Wilkie also renewed his threat to pull support for the Federal Government if his plan to tackle problem gambling is not passed by May next year.

"There's no theatre here, no grand strategy playing out. I have reached an agreement with the prime minister, she is only the prime minister because she agreed to it," he said.

Under the reforms, pokie machines will be reprogrammed to cap losses at $120 an hour rather than $1,200 an hour, but lower-intensity machines will not require any form of pre-commitment.

Mr Wilkie said he was not prepared to negotiate further on the plan.

"There's no flexibility at all, there must be mandatory pre-commitment fit to all high intensity pokie machines," he said.

He said he remained confident his proposed changes would be successful, and expects it to be law by May next year.

"I actually remain very very optimistic, I think it is most likely that these reforms will be realised. I think it is very unlikely, in fact it's now reached the stage of almost inconceivable that I will have to withdraw my support [for the Government], as everyone knows is the bottom line," he said.

Grand final ads

Meanwhile, Lobby group GetUp! was to air a commercial during Sunday's NRL grand final in support of the Gillard Government's pokie reforms.

GetUp! national director Simon Sheikh said the advertisements were aimed at countering the big spend and misinformation campaign by Clubs Australia.

"They're trying to walk both sides of the street, saying that reform will ruin the revenue they receive from problem gamblers, while at the same time saying that reform won't reduce problem gambling," he said in a statement.

Mr Sheik said a problem gambler can lose $1,200 in one hour on high-intensity machines and 40 per cent of pokie losses come from problem gamblers.

"Without reform, pokie machines enable a social problem that can ruin individuals, families, businesses and marriages," Mr Sheikh said.

"Clubs give back just 2.7 per cent of profits in community contributions and for most, this is less than what they spend advertising their pokie palaces," he said.

ABC/AAP