Protesters plan to take to Auckland Harbour Bridge later this month to demonstrate against delays building the SkyPath walkway and cycleway.

A protest march is planned across the bridge on May 26.

The march is being organised by the SkyPath Trust, which has been pushing for the project for more than a decade and believes it is being sabotaged by the NZ Transport Agency.

SkyPath director Bevan Woodward told the Weekend Herald the trust will be seeking permission from NZTA and the police for people to walk and cycle across the bridge on the western clip-ons, but is not ruling out actions of civil disobedience.

"It will be a significant occasion given it is the 60th anniversary of the bridge," he said.

A similar march occurred in 2009 when thousands of demonstrators broke through police barriers, walking and cycling across the bridge as a protest against its lack of cycle lanes. At the time, the GetAcross organisers, led by Woodward, vowed another protest if no progress was made.

Woodward said it has become apparent that NZTA has no intention of delivering SkyPath and kept coming up with disingenuous excuses for not doing anything.

Another SkyPath trustee Christine Rose said the project has resource consent, funding and the support of the public and politicians, but after 10 years NZTA is still putting obstacles in the way.

Transport Minister Phil Twyford (left) and Green Party co-leader James Shaw announced funding SkyPath in August last year.

In August last year, Transport Minister Phil Twyford and Associate Transport Minister James Shaw announced on the North Shore side of the harbour bridge that NZTA had $67m to build SkyPath.

Twyford said SkyPath was a "transformational project that will give Aucklanders the freedom to walk and cycle from the Shore to the city", but would not give a completion date.

The Herald is seeking a response from the police and NZTA on the march.

In February this year, NZTA said a business case for SkyPath is well under way and construction could start late next year.

In 1975, Dame Whina Cooper led Maori land protesters on an historic march over the Auckland Harbour Bridge and in 2004 police granted permission for the hikoi - protesting at the proposed foreshore and seabed legislation - to cross the bridge.

In April 1998, 16 people were arrested on the bridge after the police would not allow protesters marching against the Multilateral Agreement on Investment to walk across.

Every year, part of the bridge is closed for runners participating in the Auckland Marathon.

The organisers of the May 26 march are asking people to gather at Point Erin Park at the city end of the bridge at 9am.

Tamaki Makaurau road policing manager Inspector Scott Webb said police were aware of the plans.

Any group planning such an event was required to submit a traffic management plan "due to the significant safety issues posed, which in this case is required to be approved by NZTA".

"Any involvement of Police would be at the request of the authorising agency and our role would primarily be as a preventative measure to ensure the safety of the group and to ensure there is minimal disruption to commuters."

A NZTA spokesman said it was committed to building a walking and cycling link over the Auckland Harbour Bridge and work was "well under way" on a business case.

"So far, the business case process has been looking at a number of design options that could be possible, and we need to do more work before we know the right design to take forward. The earliest construction could commence would be late 2020."

Construction could take two and a half years.

Simpson Grierson was also leading an independent investigation into the Transport Agency's previous dealings with the SkyPath Trust.

"The investigation will examine whether the Transport Agency, through its employees or representatives, entered into any commercial arrangements with the SkyPath Trust, whether the Transport Agency, through its employees or representatives, promised or created an expectation that it would procure services from the Trust where it would be involved in designing, building or operating the walking and cycling crossing of the Auckland Harbour Bridge. We anticipate receiving the investigation's findings shortly."

The agency would provide SkyPath Trust with information on how to make an application for a road closure.