The Government is unlikely to introduce recommended levy increases on bikers, ACC Minister Nick Smith said yesterday after a huge protest rally outside Parliament.

The demo pulled in about 5000 motorcyclists incensed by ACC's proposal to hike their levies on the grounds that they're having more accidents.

On Parliament's forecourt they drowned out Dr Smith with shouts of "bullshit, bullshit" but later had a quieter meeting with him in the Beehive.

"I've indicated to them that it's unlikely that the Government will agree to the scale of increase that the ACC board has recommended," Dr Smith later told reporters.

The show of anger from the 6000-strong "bikoi" was concerning enough for Dr Smith to be flanked by the police bodyguards usually reserved for Prime Minister John Key when he fronted them.

Organiser Brent Hutchison said he could understand why Dr Smith had the bodyguards.

"There's an angry mob out here calling for the minister's head. It would be lax if the Diplomatic Squad did not stand by him."

Mr Hutchison said he received an email this week from a biker "trying to incite this into a riot" but had worked with police to stamp it out and ensure the protest was peaceful.

The protest ride saw 50cc "nifty fiftys" and massive "road hogs" cruise alongside each other united at being singled out for annual levy rises of between $198 for mopeds and $493 for 600cc-plus machines.

Goatee beards were a popular fashion accessory, and nicknames like "Stoney", "Hawkeye" and "Wolfman" plentiful. But Parliament's lawn was also filled with clean-cut office workers with helmets tucked under their arms.

Labour leader and biker Phil Goff dismissed the statistics the Government were using to justify the rises for the motorcyclists as "crap - absolutely crap".

He said they were often the fault of cars, as in his own crash when "a car ignored a Give Way sign and cleaned me out on the way through".

Mr Goff reflected the disappointment of many of the crowd at not being able to ride their bikes into Parliament's grounds, noting it was okay for National MP Shane Ardern to be able to drive a tractor up the steps "but it is not good enough for us".

Labour MP Rick Barker, clad in full leathers after riding down from Hawkes Bay on his Triumph Rocket III, railed against the way the system had always been against bikers.

Protest organisers counted 3000 bikers on State Highway One, 1800 on State Highway Two and hundreds more already in Wellington in a far bigger turnout than expected.

- Additional reporting NZPA