A motion to allow the ministerial code to be policed independently of the Welsh government and the national assembly was rejected in the chamber on 21 November 2012.
The ministerial code provides guidance to ministers on how they should act and arrange their affairs in order to uphold certain standards.
The Liberal Democrats brought forward the motion during their allocated debating time although they stressed that there are no issues with current ministers.
Party leader Kirsty Williams AM called on the government to follow Scotland and Northern Ireland's lead and appoint an independent advisor on the ministerial code.
Speaking on behalf of the Conservatives, Andrew RT Davies AM voiced their support for the motion as he asked for a clear timetable for consultation and implementation of the idea.
Plaid Cymru's Leanne Wood warned that "transparency has become clouded" and argued that the office holder "can not investigate its own options".
First Minister Carwyn Jones rejected the motion and the amendment as he told AMs that there are "sufficient checks and balances in current system" and that "there is no suggestion that the current system has failed".
"I fail to see how the system in London is better than here," said Mr Jones as he explained that the independent advisor in Westminster only investigates cases referred by the prime minister.
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