Sherwood said

[Personally, I do not agree with other posters that the covenant is definitely still enforceable. There is a process for overturning old and obsolete restrictive covenants.]

You are quite right. I have just looked into this and it there is no guarantee that the covenant will be upheld. Indeed the fact that Lewisham granted planning permission will probably help the cause of the nursery.

If the owners of the business knew of the covenant's existence, it is a shame that they did not think about seeking its release via the Lands Tribunal before opening their business. If they had done that then perhaps this thread wouldn't be so long.