The Institute of Public Affairs has joined the backlash against the Coalition’s decision to dump proposed changes to section 18C of the Racial Discrimination Act.

The decision announced by Prime Minister Tony Abbott on Tuesday has been welcomed by many politicians and interest groups, but the executive director of the right-wing think tank described the move as “incredibly disappointing”.

Executive Director John Roskam said Mr Abbott’s promise to repeal the legislation was made repeatedly, including at the IPA’s 70th Anniversary Dinner last year.

“Abandoning the repeal of section 18C of the Racial Discrimination Act is a broken promise,” Mr Roskam said.

“Freedom of speech is fundamental to democracy. If people are not free to debate and discuss ideas then we no longer live in a free society. To retain section 18C is to reject basic liberal principles.

“It is extremely disappointing that the Coalition no longer regards restoring free speech as a priority. Nothing is more important than freedom of speech – it is our most important freedom.”