Acting prime minister Warren Truss says race-hate laws don’t need to be changed for people to speak their minds about issues they feel are important.

South Australian Senator Cory Bernardi has renewed calls for changes to the Racial Discrimination Act to allow unfettered debate of terrorism and other issues, following the Paris terror attacks and the Martin Place siege in Sydney.

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The government last year dropped plans to amend section 18c of the act, which makes it illegal to offend, insult or humiliate people on the grounds of race.

Senator Bernardi says the act stifles freedom of speech and stops people from discussing controversial issues because they’re fearful of causing offence.

But Mr Truss says people can still make their opinions known without using race as a factor.

“We should be bold and speak out about the things we want to speak out about but we can do that without changing section 18c,” Mr Truss told AAP.

“The government’s come to a decision in relation to that issue and we’re not proposing to change.”

More than three million people in France have marched against terrorism.

People turned out on the streets of Paris on Sunday to pay tribute to the victims of three days of terrorist attacks that left 17 people dead.

The crowd chanted “Charlie, Charlie”, in honour of the cartoonists and journalists killed at Charlie Hebdo over its lampooning of the Prophet Mohammed.

Mr Truss said incidents such as those in Paris and Sydney were “evil” and had nothing to do with race issues.

“We should rightly condemn it,” he said.

Attorney-General George Brandis used a newspaper column to state that the attacks in Paris showed the world was in for a long fight with Islamic extremists.

“There can now be no rational person who still disputes that the world – and the free and democratic nations of the West in particular – (is) facing a profound threat that is likely to be with us for a long time,” Senator Brandis wrote in The Australian.