OTTAWA -- A few weeks ago, Prime Minister Justin Trudeau helped raise a pride flag on Parliament Hill and promised to erase convictions for Canadians found guilty of sexual activity with a same-sex partner under old laws. But his government has yet to move forward on a bill that would eliminate an old anti-gay law.

The Liberals have tabled two bills that would eliminate an old law barring anal sex, section 159 of the Criminal Code. The first, C-32, was tabled last November and hasn't moved past first reading. The second, C-39, which contains other changes to eliminate "zombie laws" that are still on the books but have been found invalid, was tabled in March and hasn't moved past first reading either.

Now, Trudeau is promising to introduce legislation to let Canadians erase convictions under "historical, unjust laws for sexual activity with a same-sex partner." He says it will be introduced later this year.

But his end-of-sitting announcement of new legislation stands in contrast to the delay in debating eliminating the defunct ban on anal sex.

Edmonton MP Randy Boissonnault, Trudeau's special adviser on LGBTQ2 issues, chalks it up to a timing issue.

"The House calendar continues into the fall as well," he said in an interview with CTVNews.ca.

"It's just a timing thing in terms of the volume of what can happen in the House... It's part of our plan and we are coming back in the fall to do this work."

'We will move ahead'

While Boissonnault said part of his secretariat's role is to work with different ministries and with the House leader's office on the legislation, he referred questions about delays to Government House Leader Bardish Chagger, as did Justice Minister Jody Wilson-Raybould's spokesman.

Chagger's spokesman said the Liberals are committed to the Charter and to "long-overdue changes" changes to the Criminal Code.

"We will move ahead with our proposed legislation in the coming months," Mark Kennedy wrote in an email to CTVNews.ca.

(Wilson-Raybould's spokesman says the government decided to put the measure from C-32 into C-39 and move it forward as one bill instead of two, and that he hopes the House takes it up for debate "sooner rather than later.")

In the meantime, Boissonnault said, the existing law has been found unconstitutional by five Canadian courts: the Federal Court and courts in British Columbia, Ontario, Quebec and Nova Scotia.

But that doesn't stop mistakes from happening. A Nova Scotia judge convicted a man under s. 159 in April, 2016, although the Crown later conceded that had to be set aside because it is unconstitutional.

These zombie provisions "wreak havoc because there's often errors that are made by police, by Crowns, by judges," said Kyle Kirkup, a law professor at the University of Ottawa.

"[It] should be a fairly easy endeavour. It's a simple Criminal Code fix. So I'm surprised that there hasn't been any movement," he said.

'Want to see some movement' on promises

In a year in which his government was criticized for how little legislation was passed, eliminating a law that's already been invalidated seems like an easy way for the Liberals to improve their total.

"It could be one of their winners when there's not a lot of pieces of legislation actually getting passed," Kirkup said.

The legislation Trudeau promised to introduce to erase convictions for sexual activity with a same-sex partner, on the other hand, is a complicated endeavour, Kirkup added.

"You have to think about how are you going to develop a system to expunge those convictions while keeping other sexual assault convictions still on the books," he said.

"The key is that there's a really clear process for people about how they go about expunging the convictions. I think that anything too complicated or that takes too much time is only going to add more anxiety to something that is painful for many people."

Kirkup says the expungement process should take priority over the bill to remove the zombie laws from the Criminal Code

"A lot of the people that have been charged with these provisions unfortunately... have died with these discriminatory convictions on their records," he said.

"We really want to see some movement on bills that they promised to change."