Auckland port workers will celebrate Labour Day today in the time-honoured tradition of the campaigning 19th-century Wellington carpenter Samuel Parnell - by going on strike again.

Although the strike by the 265 workers against the port company's two container terminals will be only for a symbolic three hours and 15 minutes from 10 am, the Maritime Union is inviting family members and supporters to join them at information pickets outside both sites, where there will be barbecues to celebrate the public holiday.

Information pickets differ from hard action by not being aimed at stopping traffic from reaching the wharves, which will remain open for non-containerised freight, but closed to container trucks between 9 am and 1:30 pm.

And although the strike will be the fifth held by the union for a pay rise of 4.5 percent to 4.9 percent and allowances which the port company warns will boost labour costs by more than 10 percent, no more notices of industrial action have been served ahead of enhanced negotiations due to begin tomorrow.

Unionists pay tribute every Labour Day to the stand taken by Parnell at Petone in 1840 in insisting he would work no more than eight hours a day, leaving eight hours to sleep and eight hours for men to do what little things they can for themselves.

Maritime Union advocate and branch president Denis Carlisle said the latest strike was to highlight that, despite Parnell's efforts, Labour Day was usually a normal working day at the port.

The negotiations tomorrow and on Friday will be held before a facilitator from the Employment Relations Authority, which agreed last week to a request by the port company to become involved under a rarely- invoked provision in industrial law.

Carlisle said his negotiating team had decided against lodging any more strike notices in the meantime in opposition to the company's offer of a 3.25 per cent pay rise for each of three years.

Unlike during a 48-hour strike three weeks ago, when one container ship bypassed Auckland and several others were disrupted, the port company says there will be no impact on vessels today.