Bikers in central London are arguing against a £1-a-day parking charge introduced by the council.
The legality of the parking order made by Westminster City Council is being challenged in the High Court by the "No To Bike Parking Tax" campaign.
Chairman of the campaign, Warren Djanogly, has accused the council of exceeding its powers and is asking the court to rule that the charges are invalid and unlawful.
The daily fee would be an unwelcome outgoing for motorcyclists, who may already feel that the bike insurance and road tax they must pay is too high.
Mr Djanogly believes the charges are unnecessary as they have no benefit to traffic management.
The orders, which came into force in January, were made under provisions of the 1984 Road Traffic Regulation Act and replaced experimental orders introduced in 2008.
Campaign lawyers will argue they were introduced for "an improper purpose", namely the raising of revenue, following inadequate consultation and reliance on inaccurate cost and revenue figures.
The parking charges have already triggered protests on the streets, with bikers spray-painting signs.
There is no suggestion that Mr Djanogly's campaign group is involved, and it has sought to distance itself from the attacks.
The orders impose a £1-a-day charge for motorcyclists, except for residents' permit holders.
Alternatively, motorcyclists can pay £3.50 a week, £13.50 a month, £33.50 for three calendar months, or £100 a year.
© Press Association 2010