I agree with lacb, this action by Lewisham is to reduce the amount of waste that the borough produces.

For justification, see this article, for example.

Food waste will likely be quite dense in comparison to other waste due to its high water content, thus separating this and recycling it is important when trying to increase the total amount of waste recycled which is measured by weight rather than by volume.

So, samuelsen, I would urge you not to avoid recycling anything in protest as this may cause further fines leading an even more draconian recycling policy from the council.