Labour says the Government has broken faith with unions by restricting their access to workplaces.
Under changes to workplace law announced by Prime Minister John Key, union officials will have to get permission from employers to visit their members.
Labour Party leader Phil Goff says this breaches a commitment Mr Key gave to unions that changes to access were off the table.
A spokesperson for Mr Key says the change was signalled in National's 2008 election manifesto.
However, unions say it's a return to the days of the Employment Contracts Act.
The Council of Trade Unions says Mr Key told unions in 2009 that restricted access to workplaces was not on the agenda and that they would be consulted about any changes.
