There is a warning that union action at a toilet paper manufacturer could lead to a shortage of supply.

Pulp and Paper Union Kawerau union secretary Tane Phillip says supplies could dwindle because 145 workers have been locked out indefinitely without pay at Kawerau's Essity mill, the manufacturer of Purex toilet paper.

'There are no operations happening in the paper machines, the warehouse or the converting which is where they roll the paper,” he told RNZ.

”I've been into some supermarkets, and I've seen them limiting the amount of toilet paper already.”

The plant is the only place that produces toilet paper in New Zealand, while everything else is imported in.

Essity has been approached for comment.

Workers at the Kawerau manufacturing plant have been locked out since August 9, after they called for an inflation adjustment to their pay as part of collective employment agreement negotiations.

The annual rate of inflation hit 7.3 per cent in the June quarter.

The company had offered a 3 per cent pay rise plus a cash incentive of $1500 per year over three years.

Essity's brands in New Zealand include Purex, Handee, Sorbent, Libra and Tork.

A Countdown spokesperson says Essity has been in contact with the supermarket regarding the industrial action.

'We're working closely with them and our other supply partners to ensure we have enough toilet paper supply for everyone to get what they need. At this stage, we don't have any concerns about a possible shortage,” she says.

Foodstuffs has also been approached for comment.

-Stuff/Briann Mcilraith.