Parliament's bipartisan human rights committee says changes to the Racial Discrimination Act would not contravene Australia's international obligations, which supporters of change say is an endorsement of their push.
Family First Senator Bob Day has proposed removing the words "insult" and "offend" from section 18C of the act after the federal government's attempt to overhaul the entire part of the law sparked a backlash.
The parliamentary joint committee on human rights, one of Parliament's three powerful scrutiny committees, has found the changes would not breach Australia's human rights obligations.
Prime Minister Tony Abbott said he made one his 'Captain's calls' in deciding to break his election pledge to repeal the section because he needed the support of Muslim communities for tougher counter–terror laws instead.
Senator Day's amendment proposal to remove the words "insult and offend" from the act meaning it would no longer be possible to prosecute someone for insulting or offending someone.
The committee says the proposed bill is one of several pieces of legislation currently before the Parliament that "do not engage human rights".
Liberal senator Dean Smith chairs the committee. Senator Smith co-sponsored the Senator Day's amendment along with South Australian Liberal Cory Bernardi and Liberal Democrat David Leyonhjelm.
Senator Day said the report "vindicates and supports" his proposal and shows "there's no impediment" to removing the words "insult" and "offend" and hoped there would be widespread support in the Senate for change.
"I'm always hopeful, always optimistic," Senator Day told Fairfax Media.
"Hopefully now for the other senators this will be the last barrier they need [to overcome] to support my amendment," he said.
Mr Abbott made his pre-election pledge to the Institute of Public Affairs
John Roskam from the Institute of Public Affairs called on government senators to uphold their principles.
"There is now no excuse for the Coalition not to support its principles and not to support Bob Day's amendment," Mr Roskam said.
"The Coalition has to decide does it stand for freedom of speech," he added.
Labor's spokeswoman for multicultural affairs and committee member Michelle Rowland said the opposition did not believe there was any reason to water down the act and played down the human rights committee's finding.
"You would hope that every piece of legislation that comes before the committee is compliant with our international obligations," she said.