Citing a lack of need for the new laws, Senator Patrick said it was "shameful" the government was moving the discrimination legislation before "focusing on things that are really important to Australians", such as a federal anti-corruption body.
The South Australian said the draft bill contained "a whole range of different examples to try and explain how the law might work".
"That just goes to the real issue ... it's really, really hard to draw lines in relation to discrimination," he said.
"We have laws in place, and in circumstances where there really is a problem the courts can look at these issues and they can do so understanding all of the facts and the circumstances of any particular case."
A government pledge before the 2019 election, the laws aim to stop discrimination on the basis of religious beliefs in places such as workplaces, schools and clubs.
Asked if Labor would support the bill, Opposition Leader Anthony Albanese told the ABC he had not yet seen it, nor had the government sought support for it.
"Do I support religious freedom? Absolutely, but we need to see the bill," he said.
"I've spoken to religious leaders … who are very disappointed the government, on an issue which should not be an issue of partisan politics, has not worked in a bipartisan way across this parliament.
"Scott Morrison is always seeking to divide rather than bring people together."
Centre Alliance MP Rebekha Sharkie had also not seen the bill, but questioned why it had been given priority having "not met a person who said they have been discriminated against on religious grounds".
The draft bill is expected to go to the coalition party room on Tuesday, but there is no indication yet when it will come to parliament.