Talks between the Lyttelton Port Company and the Rail and Maritime Transport Union have failed yet again.
Pay and safety are the main sticking points.
The port and the union met for several hours today after the union withdrew strike notices from today until next Tuesday.
However, union spokesperson John Kerr said talks did not progress.
Mr Kerr said the union put forward eight scenarios that could have led to a settlement, but the port company would not move its position.
"We just want to get this fixed. This has been hugely difficult. It has been the most acrimonious round of bargaining that I've experienced in 20 years of being a union organiser."
Mr Kerr said strike action would continue from next Tuesday.
The port's operations manager Paul Monk said the port would not comment on negotiations as both parties had agreed on confidentiality.
But Mr Monk said the five-day strike that was planned next week needed to be withdrawn today, otherwise ships would not be able to come into the port during that time.