Industrial action at Lyttelton Port is being ratcheted up a notch today with workers planning to block the road and train tunnels to the port.
Members of the Rail and Maritime Transport Union have been on strike since Wednesday in support of improved pay and conditions.
At 1pm, the rail tunnel connecting the port to Christchurch will be blockaded by some of the 200 striking union members.
They were confident fellow union members driving trains would not attempt to breach their picket line.
Then at 2pm, union members will attempt to march through the Lyttelton road tunnel, holding up traffic to or from the port.
Workers were refusing to return to work until Sunday which had prevented ships entering the port.
The Lyttelton Port Company was approached for comment but had yet to respond.