The bread aisle at the Edmonton Rd Countdown in Te Atatu South was almost empty during last week's strike.

Bread supplies could run short after workers at George Weston Foods' Tip Top bakeries resumed strike action, the company says.

George Weston Foods baking division general manager Mark Bosomworth said bread shortages were expected in parts of the lower North Island and north of Auckland.

First Union organiser Anita Rosentreter said more than 100 First Union members were refusing to work overtime and do deep cleaning at the Ōtāhuhu and Wiri bakeries.

The union said the company – which also manufacturers Ploughmans and Bürgen bread – had refused to offer fair pay and a premium on overtime and night work.

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Bosomworth said the strike would affect customers from Kapiti Coast to Wairarapa and also north to Kaitaia. Additional staff had been deployed to the affected bakeries, he said.

Countdown said there would be minimal disruption of supply to its upper North Island supermarkets. Its in-store bakeries would supply fresh baked bread, and work with other suppliers to increase production where possible.

Foodstuffs said it had alternative suppliers.

Rosentreter said a ban on overtime and deep cleaning had been put in place after workers universally rejected an offer made by George Weston Foods last Wednesday. The bans were in place from Sunday.

SUPPLIED Crate washer Sapulu Falesefulu says he has to work extra hours to make enough to live on. He is contracted to work nine hours a day.

Workers met on Friday to discuss the offer, which Rosentreter said did not meet expectations. There had been an offer of a 4 per cent general wage increase for some staff, and overtime starting at 57 hours, down from 60, "but would only apply from September next year," she said.

Bosomworth said workers at the Ōtāhuhu bread lines and Wiri lines for bun and roll, crumpets and gluten free products would continue with industrial action until an agreement had been reached.

"While staffing levels will be low, we are doing everything we can to minimise disruption to our supply chain ... we are negotiating in good faith," he said.

Sapulu Falesefulu, a crate wash operator at the George Weston Foods Tip Top factory in Auckland, said working a 45 hour week didn't bring in enough to cover the cost of living.

Falesefulu was among the workers who went on strike early last week at the factory, which resulted in a bread shortage in the upper North Island.

SUPPLIED Union delegate Empson Pine says workers often don't get to see their children at the end of long night shifts.

He had worked at the company for 14 years but said his hourly rate of $22.16 did not reflect his service to the company or the cost of living in Auckland.

He has four children and is the sole bread winner for the family.

Last week his bank account became overdrawn after a number of automatic payments came out leaving him with nothing.

"I want to sort this out with my employer. Pay me a fair rate. Now we need a pay-rise and to be paid fairly for overtime hours," he said.

Rosentreter said that under the collective agreement, a normal working week is 45 hours. However, overtime was not paid until after 60 hours.

The union wants to see it kicking in after 45 hours.

Falesefulu said he regularly worked extra hours.

"I work 50 hours to make fair money for my family. But for me to work more hours, it's too long for me. I feel tired," he said.

The overtime had an impact on his family life. If he worked a 10 hour shift or longer there was no time left to spend with his family.

JOHN BISSET/STUFF Timaru-based IDEA Services workers, who went on strike earlier this year, said they were worried about poor working conditions.

Union delegate Empson Pine said this was a common story among workers at the factory.

Staff often worked as many as 50 hours but "hardly ever" reached the 60 hours required to get paid overtime, he said.

Bosomworth said the company paid competitive rates and provided good training and a safe working environment.

Rosentreter said some other bakeries had committed to paying "no less than the living wage" with other rates tied to qualifications and skills.