The corruption watchdog last year found that Ryde councillors Justin Li, Terry Perram and Jeff Salvestro-Martin, plus former councillors Ivan Petch and Victor Tagg, should be considered for prosecution for allegedly breaching election funding laws.

The alleged offences related to political advertisements that appeared in local newspaper The Weekly Times in the lead-up to the 2012 local government elections.

But the NSW Electoral Commission said on Wednesday that it had decided that it would not proceed with the prosecutions.

"After careful consideration, the commission has formed the view that there is insufficient admissible evidence to commence proceedings against any of the named persons," the statement said.

Mr Petch, a former Ryde mayor, is separately being prosecuted for misconduct in public office, blackmail and giving false or misleading evidence to a corruption inquiry.

Those criminal charges stem from a 2013 Independent Commission Against Corruption investigation into Ryde City Council that made a series of corrupt conduct findings against Mr Petch and others.

The matter is listed for mention at the Downing Centre Local Court on September 3.