"It's pretty significant actually, if you look at the ports of Auckland and the ongoing dispute there _ the ports of Auckland could have walked away from bargaining and it's the same with Talleys/Affco.
"Moves to destabilise collective bargaining undermine the effort and pride New Zealanders put into their work,'' she said.
Prime Minister John Key said National had campaigned on the changes but admitted it had not campaigned to level out the amount of time unions and employers have to initiate collective bargaining.
"At the moment it's 40 days for an employer and 20 days for a union. We don't think it makes sense to have a differential date, so we'll have the same date,'' said Mr Key.
President of the Council of Trade Unions Helen Kelly said the Government had a responsibility to promote collective bargaining.
"Instead they are undermining it and they know this will further reduce pay and conditions for New Zealand workers.''
She said the removal of the duty to conclude collective bargaining will be seen as the "Port of Auckland clause'' because the Government knows that the port wanted to abandon collective bargaining and instead begin contracting out.
Ms Kelly said deductions from workers' pay for partial strike action is another attack on the rights of workers. "It is designed to force workers either into a full strike or to abandon any action.''