Leeds Council made the decision despite the murder of a Polish sex worker in Holbeck in the last fortnight.
Holbeck Christian Fellowship has said the scheme is poorly managed, with sex workers often straying out of the designated area and putting themselves at risk as a result.
It operates in the Holbeck area in the south of Leeds, and allows prostitutes to solicit between 7pm and 7am without fear of arrest.
Some have criticised the scheme, saying it is negatively affecting local businesses and legalising something which is normally a crime.
Leeds Council has said the scheme has improved the safety of sex workers, encouraged them to report crimes against them and improved strained community relations.
However David Hebden, from Holbeck Christian Fellowship, said the death of the Polish sex worker shows they're wrong: "The Polish girl that was killed about ten days ago - I don't think she'd agree with it. And I don't think that, like I said earlier, the managed part of it is not particularly [well] managed.
"It is supposed to be a managed scheme, but unfortunately I don't think there seems to be a lot of management. One of the girls was killed just over a week ago, and they do tend to stray out of the area where they're supposed to be working.
"I think they're just hoping it will go away. They're hoping something will happen - that it just disappears from view.
"I know because I'm part of a foodbank in Holbeck and we supply some of the girls with food occasionally. It's going to be an ongoing situation."
Cllr Mark Dobson, Leeds City Council's executive member for the Safer Leeds scheme, said: "I accept that there are people who will always have a moral objection to the issue of prostitution.
"I'm of the opinion that it is an industry that's as old as time and it isn't going to stop and, as a city that is responsible and cares about the people who live here – including the women who work in this industry – we have had to take a pragmatic approach to keep them safe.
"The managed area isn't a universal cure-all. Sex work remains – as last month proved – an extremely dangerous and fraught occupation.
"But it's incumbent on us to make it as safe as possible."
Listen to Premier's Aaron James speaking to David Hebden: