The West Australian Government hopes to implement new prostitution laws by the end of its second term, despite opposition from Liberal MPs.

The Barnett Government introduced legislation in 2011 that would have allowed brothels to operate in some zones but outlawed sex workers operating privately in residential areas.

It would also have required workers to obtain and display a "prostitute licence".

However, the bill was stalled in the lower house by the Opposition and some Liberal MPs, some of whom were pushing for a sunset clause that would outlaw prostitution within a few years.

Attorney General Michael Mischin told Parliament he hoped to pass new laws before the next election, but conceded that opposition from some in his own party was a major stumbling block.

Mr Mischin said introducing the new laws was still on the Government's agenda but a challenging issue.

"There are difficulties with the prostitution legislation that are being addressed, and I'm trying to find a way of doing that which will provide a level of control that will enhance police powers," he said.

Labor spokeswoman Sue Ellery said the lack of action on the issue was not good enough.

"We're operating in a legal vacuum and it needs to be fixed and your government promised to fix it," she said.