Labour now wants to talk to ACT MP Heather Roy about a bill which would give students the right to chose whether to join a student union or not.
Ms Roy accuses Labour of abusing Parliamentary process, by deliberately dragging out debate on non-controversial legislation to delay the Education (Freedom of Association) Amendment Bill.
Chief Whip Rick Barker said that Labour is willing to debate the bill, but it has some concerns about its context.
He said the problem is that it makes voluntarism - compulsory.
Mr Barker said Labour would like to negotiate with Ms Roy on how to proceed before voting on it.
Ms Roy said it was the first time she has heard of Labour's concerns.
