Many Australians of faith believe Labor does not care about them and the party must address the sentiment urgently, frontbencher Chris Bowen believes.
Mr Bowen has highlighted the perceptions of Labor among religious people while bowing out of the race for the party's leadership, saying it had been part of his motivation for running.
"I have noticed as I have been around during the election campaign and even in the days since ... how often it has been raised with me that people of faith no longer feel that progressive politics cares about them," he told reporters in Sydney.
"These are people with a social conscience, who want to be included in the progressive movement.
"We need to tackle this urgently. I think this is an issue from the federal election that we haven't yet focused on."
The comments come after the Australian Christian Lobby hailed the coalition's election victory on the weekend as a win for religious freedom.
Mr Bowen's seat of McMahon in Sydney's west was among Labor electorates targeted by the ACL, which believes the coalition has a better position on issues such as freedoms for faith-based schools.
"The policy difference between the two major parties on religious freedom was very clear," ACL managing director Martyn Iles said.
Religion cropped up during the campaign, with resigned Labor leader Bill Shorten denying he had politicised Scott Morrison's faith by saying the prime minister should have made it clearer that he doesn't think gay people go to hell, when he was asked if he did.
"I do respect the right to religious freedom. I do respect freedom of speech," he told ABC's 7:30 soon after.
"But I also respect that just as religion is part of someone's identity, so is their sexuality."
Responding to Mr Bowen's comments, Labor MP Anthony Chisholm says he doesn't believe his party has alienated some voters by becoming too progressive.
"From my point of view it's more around that economic reassurance and ensuring Queenslanders understand that we will be responsible economic managers," he told ABC TV.
Australian Associated Press