In a move that has delighted the right of the Coalition and dismayed MPs who hold marginal seats or represent ethnic communities, Mr Turnbull and Attorney-General George Brandis unveiled changes to the language of section 18C of the Racial Discrimination Act.

Changes to how the Human Rights Commission handles complaints under the Racial Discrimination Act are also on the way.

The Commission president, currently Gillian Triggs, will have to rule early on whether a complaint has merit and should proceed; complaints will have to be lodged within six months of an incident, and then dealt with more quickly - within 12 months.

Mr Turnbull said the changes would strengthen freedom of speech in Australia and ensure protection from racism.

"We are defending Australians from racial vilification by replacing language which has lost credibility," he said.

"We need to restore confidence to the Racial Discrimination Act and to the Human Rights Commission's administration of it."

"This is an issue of values - free speech, free speech is a value at the very core of our party. It should be at the core of every party. Ensuring Australians are protected from racial vilification, likewise, is part of the mutual respect of which I often speak."

Mr Turnbull would not say if it would be acceptable to call someone a "wog" under the proposed changes, and declined to repeat the term when put to him.

The Prime Minister predicted Labor would "cynically and ruthlessly" exploit the proposed changes, which, will - unusually - first be introduced in the Senate by Senator Brandis.

Labor's Tony Burke suggested the bill would go to the Senate first because "if they can't get it through the Senate, they don't want to force their own back bench to have to vote for it"

The proposed changes to the wording of the act, which bring to a head years of debate, are all but certain to be defeated in the Senate by Labor, the Greens and the Nick Xenophon Team.

They will also trigger a campaign from activist group GetUp!, concern ethnic communities, who strongly opposed the changes back in 2014, and win support from free market think tank the Institute of Public Affairs.

Earlier, during debate in the Coalition party room, Deputy Prime Minister Barnaby Joyce warned that dragging out debate on the issue could cost the Coalition votes.

Former prime minister Tony Abbott praised Mr Turnbull and Senator Brandis during the party room discussion, while Development Minister Concetta Fierravanti-Wells warned changing section 18C of the Racial Discrimination Act would be very unpopular with multicultural communities.

The proposal will see the words "offend, insult and humiliate" removed from the act and replaced by "harass" while "intimidate" will remain.

The debate about changing Australia's race hate laws was held on National Harmony Day and the International Day for the Elimination of Racial Discrimination.

Mr Joyce's warning to the party room was in line with similar comments he has made about the fractious same-sex marriage debate - that, essentially, voters are not concerned about section 18C but are more concerned about day to day issues and that the Coalition should stop talking about the issue.

Several MPs rose to disagree with Mr Joyce, including South Australian Liberal Tony Pasin and WA Liberal Andrew Hastie.

Sources in the room told Fairfax Media that Mr Hastie argued changing 18C was about "de-fanging the operational arm of the political correctness movement in this country".

Mr Pasin disagreed with Mr Joyce and said voters in his electorate raised the issue with him.

About 20 MPs spoke during the meeting and the strong majority ultimately agreed with the package of changes, which was ticked off by cabinet on Monday night.

Those who argued for change included leading proponents Tim Wilson and James Paterson, Mr Abbott, Eric Abetz, Mr Pasin, Mr Hastie and George Christensen.

Those who spoke against changing the wording of the act included MPs Craig Laundy, David Coleman, Ann Sudmalis and John Alexander.

Mr Laundy, who holds the marginal western Sydney seat of Reid, told ABC radio before the meeting that he would stand up for his multicultural electorate during the debate and that he was comfortable with section 18C of the act.

Senator Abetz released a statement after the meeting praising the proposed changes: "These common-sense reforms will go a long way to ensuring that Australians can engage in free speech while maintaining protections against racially motivated harassment and intimidation".

Opposition Leader Bill Shorten, meanwhile, told the Labor caucus meeting that the prime minister was moving ahead with changes to 18C - and penalty rates - because "they'll never affect him".

Follow us on Facebook

Follow James Massola on Facebook