Attorney-General George Brandis will have the power to block legal action or appeal an injunction. Credit:Alex Ellinghausen "It will be unlawful to vilify, intimidate or threaten to harm a person either because of views they hold on the survey or in relation to their religious conviction, sexual orientation, gender identity or intersex status," a government spokesman said. "That will be a sunset provision, it will only last for the period of the postal plebiscite." The protections are similar to those already enacted in various state jurisdictions around Australia but do not currently exist at a Commonwealth level. The laws, to be rushed through both chambers of Parliament by Thursday night, will apply to "conduct" during the campaign, which could include advertising, leaflet materials or behaviour.

Judges will have the power to injunct any materials subject to an alleged breach, but Senator Brandis will also have the power to appeal that injunction. Acting Special Minister of State Mathias Cormann told the Coalition party room Senator Brandis would no doubt approach the issue of "with a bias toward freedom of speech". The Turnbull government has been negotiating the bill, first revealed by Fairfax Media, with shadow attorney-general Mark Dreyfus, and Labor is expected to back the measures. The bill will also import a number of safeguards from the Commonwealth Electoral Act, such as a requirement that campaign materials bear an authorisation, and apply them to the postal survey campaign. The usual safeguards do not automatically apply because the survey is being conducted under the auspices of the Census and Statistics Act, through the Australian Bureau of Statistics, rather than the Australia Electoral Commission.

Tuesday's Coalition party room meeting green-lighted the new laws despite internal dissent from Liberal MP Tim Wilson, who had concerns about freedom of speech. He was backed by his former employer, the libertarian Institute of Public Affairs think tank, whose director Simon Breheny accused the Coalition of "playing with fire". "Vilification laws are used to silence opponents," he said. "These laws are a dangerous limitation on individual freedom." Meanwhile, in an opinion piece for Fairfax Media, former prime minister Tony Abbott laid out the case for a "no" vote. He argued it had been years "since gay people have been discriminated against, and just about everyone old enough to remember that time is invariably embarrassed at the intolerance that was once common".

However, the former PM went on to say same-sex couples in settled domestic relationships "have exactly the same rights as people who are married". "To demand 'marriage equality', therefore, is quite misleading. Same-sex couples already have that," Mr Abbott wrote. "This debate is about changing marriage, not extending it. And if you change marriage, you change society; because marriage is the basis of family; and family is the foundation of community." The former prime minister also charged supporters of the legal change for being primarily responsible for bullying and hate speech in public debate, rather than same-sex marriage opponents. "It's striking how little love the supporters of same-sex marriage are showing for anyone who disagrees with them," he argued.