City mayor Sir Peter Soulsby has written to each of them warning of the consequences should they keep up their protests.
So far, the cabbies’ actions have cost them just business, goodwill and public support. Now it threatens to get a whole lot worse.
Sir Peter is promising to review the privileges and concessions allowed to Hackney cabs. A move which could cost them their livelihood.
It could mean them being denied exclusive use of bus lanes, and the bus gates in Charles Street and Causeway Lane.
It could also see a reduction in the amount of road space dedicated to taxi ranks and place a question mark over plans for new ranks.
There may also be extra focus on vehicle safety, with a review of the condition and age policy for Hackney carriages.
But perhaps most significantly of all, Sir Peter may be tempted to waive a voluntary restriction on the number of new licences the city council issues.
This could open the floodgates to more than 120 new drivers who are currently on its waiting list.
There are 120 drivers who have already indicated they are prepared to sign up to the penalty points system.
Frankly, it is easy to see why the city mayor is running out of patience.
The go-slow protest drives by cabbies have been deliberately planned to cause maximum disruption to the city and its travelling public.
Like every working man, cabbies have a right to withdraw their labour. For a day, half-a-day, or just an hour. Whatever they choose.
But rather than taking their vehicles off the roads in a symbolic “strike”, they choose instead to paralyse main arteries.
By delaying the announcement of the route for today’s planned protest, they gave us little or no time to adjust travel arrangements. That will be seen as provocative.
End it now. While you still have a business worth the name.