CTC originally co-signed a letter  in February 2014 to Leon Daniels, TfL's managing director of surface transport, urging him to instruct bus, van and taxi operators to remove the sign. The letter also calls for a reworded sign. Co-signatories of the letter include LCC, road crash victims' charity RoadPeace, cycle training organisation TABS (The Association of Bikeability Schemes) and the Road Danger Reduction Forum (RDRF).
Leon Daniels has now responded , agreeing to consider a new sticker design and the possibility of asking members of TfL's Fleet Operator Recognition Scheme (FORS) to remove the stickers. However he has rejected our calls for action to remove the stickers from buses, taxis and vans.
CTC and its allies have therefore send a further joint letter  to TfL, clarifying some apparent misunderstandings about the nature of our concerns, and reiterating our request for a dialogue.
Evidence of the problem
Specifically, Leon Daniels's letter to CTC and its allies questions whether we have evidence that the sticker is causing adverse changes to the behaviour of lorry drivers. Our response therefore emphasises our wider concern that the mis-use of the sticker could also prompt a worsening of behaviour by drivers of vans, taxis and other vehicles which display these stickers. The design of the stickers, and the way they are being misused, is effectively making out that cyclists themselves are responsible for staying behind all vehicles in all circumstances, i.e. not just to avoid overtaking on the left hand side of lorries.
We specifically note the case of an inquest where lawyers acting for the driver pointed out that the vehicle involved had a "stay back" sign on it, implying that the deceased cyclist was therefore in some way at fault.
Since our letter was sent, CTC has also heard of a case where a cyclist was cut up (apparently deliberately) by a lorry driver who overtook rapidly before turning left across his path. When the cyclist remonstrated, the driver responded with abuse. The cyclist then called the driver's company (using the "How's my driving?" phone number on the back), only to be told: "Didn't you see the lorry's 'Stay Back' sticker?"
Why we are concerned
By giving the opposite message, these stickers could be entirely counter-productive to the efforts of Transport for London itself, and other councils around the UK, to adopt continental design principles. Hence the gravity of the concerns expressed by CTC and its allies.
The sticker, originally designed by TfL for the backs of lorries, has been distributed through the TfL-led 'Fleet Operator Recognition Scheme' (FORS). CTC and the other signatories to the letter agree that 'Stay Back' is appropriate advice to cyclists when approaching a poorly designed HGV from behind on the left hand side. However, it is wrong to give drivers the impression that they are legally at fault for doing so.
In Britain, cyclists' ability to cycle safely on the inside of motor vehicles at the approach to junctions (including on segregated cycle tracks) is not supported either in law or by normal UK driver behaviour. Hence cyclists are best advised either to overtake on the outside, or to stay back.
The main objection to the 'Stay Back' message, though, is its use on small vans, buses and taxis. The drivers of those vehicles all have adequate vision of the road around them and should have no difficulty being careful around cyclists and pedestrians.
Giving drivers the impression that cyclists are at fault if they're on the inside of a motor vehicle is contrary to the changes in driver awareness and behaviour we need for people of all ages and abilities to feel they can cycle safety and conveniently, including those without the confidence to move out into the road to overtake stationary or slow-moving traffic.
CTC's Campaigns & Policy Director
Charlie Lloyd, LCC's road danger reduction campaigner said: "Many people have contacted us to say these stickers are offensive and misleading.
"Even on large HGVs the 'Stay Back' message is inappropriate. We want lorries to have a warning sign appropriate to the danger which occurs when a large vehicle turns left or right.
"Drivers of vehicles with inadequate visibility need reminding of the risks from turning without care. Cyclists need reminding of the specific risks caused when large lorries turn sharply across the road."
Overtaking on the left side is perfectly lawful where traffic is slow moving or stopped. If there is no chance for that traffic to turn left then it can be the safer option. Most cycle lanes are on the left side of the road, the Highway Code warns drivers not turn left across the path of cyclists on the left side.
These (above) are the type of sticker we would like to see. The message is clear the danger is when large lorries are turning left. The wording on the left was agreed with LCC in 2006; the image on the right won a national design competition for an easily understood image.
This notice gives the false impression that it is illegal to pass vehicles on the left side of the road. A driver seeing this sign many times a day will be tempted to think any cyclist on the left is a law breaker. The driver may not take as much care as he/she should.
Such a sign could lead to drivers blaming cyclists in the case of a collision even though there is a clear duty of care for motor vehicles to look out and not turn across the path of cyclists at junctions.
Cyclists fight back
Graphic designer Riccardo Pelc has produced an alternate sticker for cyclists to wear on their backs. The image is available in A4 or A5, prices being £5 for the A5 and £8 for the A4. For information please email him at firstname.lastname@example.org