The boss of a minicab firm has been criticised for comments cyclists claim could "put their lives at risk".
Addison Lee's John Griffin wrote: "[Cyclists] leap onto a vehicle which offers them no protection except a padded plastic hat."
London Cycling Campaign (LCC) said this was "likely to put the safety... of cyclists at even greater risk."
Mr Griffin later responded by saying: "I accept that the tone of the article was perhaps a little too inflammatory."
In his initial comments, which appeared in the firm's thee magazine Add Lib, Mr Griffin's said cyclists were "throwing themselves onto some of the most congested spaces in the world".
"The influx of beginner cyclists is going to lead to an overall increase in accidents involving cyclists," he said.
"The rest of us occupying this road space have had to undergo extensive training. We are sitting inside a protected space with impact bars and air bags and paying extortionate amounts of taxes on our vehicle purchase, parking, servicing, insurance and road tax.
"It is time for us to say to cyclists: 'You want to join our gang, get trained and pay up.'"
However, LCC spokesman Mike Cavenett said: "Mr Griffin's article is only likely to incite his 3,500 drivers to behave even more irresponsibly, putting the safety of the hundreds of thousands of Londoners who cycle daily at even greater risk."
"It's hard to see how the government departments and corporate clients that currently use Addison Lee services can continue to do so without appearing to condone the chairman's complete disregard for cyclist safety."
Following the outcry, Mr Griffin issued a statement saying the article "was meant to entertain and generate debate, but the online reaction has obscured the main message that there are many inexperienced cyclists who need better training to be safe on London's busy roads".
"Contrary to what has been reported, at no point did I suggest that motorists are never to blame," he said.
"Both cyclists and motorists have a responsibility to use the roads safely."