Tasmanian workers and people with a disability would have less rights and protections under proposed federal religious freedom bills, Unions Tasmania says.
And constitutional law expert Associate Professor Luke Beck believes the laws will "profoundly weaken" Tasmania's anti-discrimination laws.
"It seems to me that a standard anti-discrimination statute was first drafted and then a series of additional provisions were thrown in to satisfy the demands of certain conservative advocates," Professor Beck said.
"Those additional provisions are poorly drafted, sometimes incoherent, afflicted with constitutional difficulties, have strange consequences and appear to be motivated by a desire to allow people to be nasty to others.
Professor Beck, who is professor of constitutional law at Monash University, said the Religious Discrimination Bill was "more than an ordinary anti-discrimination statute protecting people against religious discrimination (a 'shield')".
"It includes additional and strange provisions granting what are in effect positive rights to individuals to inflict harms on other people (a 'sword')," he said.
Professor Beck said it seemed the bill would allow people to make 'statements of belief' that insult, offend, ridicule or humiliate other people that would otherwise amount to unlawful discrimination.
In a submission to Attorney-General Christian Porter, he said under the new laws an employer would be able to tell a gay worker "being gay is a form of brokenness", a childcare provider could tell a single mother "God will judge you harshly for taking away the child's right to have a father" and an employer could refer to a male Sikh employee wearing a turban as "a towel head" without penalty.
In Unions Tasmania's submission secretary Jessica Munday said unions welcomed protection against discrimination on the basis of religion.
"We support, in principle, protecting an individual's right to freedom of thought, conscience or religion in all the usual areas of public life. But these bills do so much more than that," Ms Munday said.
"These bills will remove existing protections for Tasmanians to live a life free from discrimination.
"The bills unjustifiably privilege religious belief over all others."
Ms Munday feared for workers and people with a disability who made up most of the complaints of discrimination.
"Unions Tasmania is concerned that the proposed bills will remove important protections for people with a disability, both in and out of the workplace context, who have a demonstrated need to rely on the laws based on Equal Opportunity Tasmania's own reports," she said.
"Over half of all complaints in which discrimination were alleged or identified relate to disability discrimination."
Ms Munday said in the submission that "previous attempts to water down Tasmania's legislation had failed".
"In 2016 and 2017, there were attempts to insert a religious exemption as well as attempts to remove the words 'offended and insulted'," she wrote.
"Both attempts failed in the Legislative Council (Tasmania's Upper House) because a majority of members supported section 17(1), noting the important protections it provides for vulnerable Tasmanians.
"We are disappointed that the Morrison Liberal Government has chosen to target Tasmania's laws against the wishes of the Tasmanian Parliament who has twice considered and upheld our laws in recent years."