Butler says Senate votes being 'laundered'

Labor Party president Mark Butler believes work needs to be done on Senate voting systems to stop Australian votes being "laundered".

Mr Butler says politicians need to get the balance right if the system is reformed to stop minor parties getting Senate seats through preference deals, to ensure the public doesn't feel their choices are being restricted by parliament.

"I think people are concerned about their vote being sort of laundered, if you like, through these preference swap arrangements ... and somehow their vote ends up in a destination they didn't even think about let alone intend," he told the National Press Club on Wednesday.