Opponents of the Mt Messenger bypass project in Taranaki have a new beef with Waka Kotahi - the cost of 'Pieday Friday' although the agency is disputing the cost.

They say the staff event - also known as "Whānau Friday" - could cost up to $500,000 over the life of the project. But Waka Kotahi said it would cost about $50,000 and was good for morale.

But New Plymouth Mayor Neil Holdom - a vocal critic of Waka Kotahi's road maintenance programme - had no appetite for that argument. "If you think, what does a good employer working in a reasonable remote site do, and anybody who begrudges someone working hard an $8 pie once a month sounds pretty petty to me.

Holdom said it was a bit rich for opponents of the project, who had cost the country millions of dollars fighting it through the courts, to complain about the cost of the pies.