Unions and industry superannuation funds won an intense lobbying campaign against the banking industry to convince the Senate to defeat the federal government's attempt to reduce the power of union and employer-group representatives over the savings system.

Senators Jacqui Lambie, Glenn Lazarus, John Madigan and Nick Xenophon sided with Labor and the Greens and said they would vote down the government's trustee governance bill, which would have required more independent board members on superannuation funds.