The Institute of Advanced Motorists has been accused of unfairly focussing on motorcyclists with claims of rising casualties.
An IAM release states that 18 motorcyclists were killed or seriously injured a day from July to September 2011, up 2% on the year before.
The release says motorcycle casualties remained 'stagnant' compared to figures for cars and calls on police and government to target riders with more enforcement.
But government figures covering a full year show that motorcycle casualties dropped by 2% and are stagnating no more than those of pedestrians, which also fell 2%.
And motorcyclists are far outperforming cyclists, who saw a 4% rise in casualties and an 8% increase in deaths and serious injuries.
Chris Hodder, Government Relations Executive of the British Motorcyclists Federation, said: “The IAM has unfairly focussed on motorcycles because they've just picked one particular quarter of 2011 that seems to show the opposite trend to the whole year.
“You've got to be very cautious about picking one quarter out. It's better to take an average over a longer period. One quarter can show a rise while the rest shows a significant fall.”
The IAM release says that '18 motorcyclists were killed or seriously injured every day between July to September 2011 - an increase of 2% compared to the same period in 2010...
'While all casualties among car users have reduced by 7%, the figures for motorcyclists have remained stagnant.'
The group's director of policy and research, Neil Greig, adds: “The police and councils must continue to work together to improve high risk routes, encourage post test training and target bad riding behaviour through innovative enforcement techniques.”
But the Department for Transport report on which the claims are based shows motorcycle casualties fell in the 12 months to September.
The DfT release says: 'Pedestrian, motorcycle and car user casualties reported to the police showed overall reductions of 2%, 2% and 7% respectively compared with the year ending September 2010.
'Pedestrian, motorcycle and car user killed-and-seriously-injured casualties also fell, by 2%, 1% and 7% respectively compared with the previous 12 months.
'However, the total number of reported pedal cycle casualties rose by 4% and the number killed or seriously injured rose by 8% compared to the 12-month period ending September 2010.'
An IAM spokeswoman said the release focussed on July to September because that was the latest three-month period to be covered by DfT data. She said car and cycle casualties were addressed in a separate release.
“We were just focussing on those statistics that were new,” she said. “We will be looking at longer-term trends in more detail over the coming weeks.” She added that motorcycle casualties were stagnating in relation to those of car users.
Hodder said the trend was down to advances in car occupant safety. "You can't really have side-impact protection systems for pedestrians or motorcycles," he added.