I needed some bike lights so popped out to Wilkinsons as they were selling some good cheap ones recently.
They were no longer in stock, but there were some other cheapo LED lights, branded RAC (yes, the motoring organisation).
On the back is the following
Important
You must not use the lamps as cycle lights on their own, but only in addition to cycle lamps complying with BS6102/3. A flashing rear lamp is not allowed on the public highway
errrr...... yes it is legal to use a flashing LED, and has been since October 2005
Also, if the flashing lights meet certain requirements, which these seem to, they can be the only lights we need - so I can use these lights on their own