There seems to be a lot of fuss in the Sussex Express about development at Old Malling Farm. This is all a bit late – by some 5 years!
The principle of development at Old Malling Farm was decided by the Government’s inspector in 2015. More info here on the Friends of Lewes web site
As a result of the Inspector’s decision the site was included in the Core Strategy Plan and was adopted by Lewes District Council on 11 May 2016. In planning terms a fait accompli. See:
The development is now part of the of the South Downs National Park Local Plan, See page 226/227. SDNPA Policy SD76 plan extract:
Site – Old Malling Farm
Save Lewes Architecture 
The fuss you describe is about the current application. It is in my opinion a poor development for the site. In addition to the lack of truly affordable homes it offers no community infrastructure. No community facilities, no shops, no pubs, no cafes etc.. Malling currently has one shop and the community centre. For such a new development it should not be allowed to be merely a dull and lazy commuter development.
Dear Merlin, yes of course but the principle of development on this site was made in 2015. Of course there is a detailed planning application to deal with but if it were to be refused it would inevitably be allowed on appeal by the Government