There is nothing new on this after SERA 1016 & Brexit 2021 (we check it regularly), however, CAA can change UKSERA with strike of pen of course now to ban this if they want (they did change Delta airspace VMC minima in UKSERA)
That’s always been the case under Rule 5, but it’s also “always” been the case that the CAA regarded the terrain down there as not qualifying for an emergency landing for the purposes of Rule 5.
Sorry for my ignorance, where is Rule 5 now? (section: low flying prohibition, failure of power unit), AFAIK, that section does not exist in UK ANO, also, who cares what CAA “always regarded” in internal policy, if that no longer exist? it’s not in ANO2016, not even in ANO2009, it’s in ANO1996, so single engine flights over London before 2009 were illegal, those after are legal
A bit like saying NVFR is illegal in Netherlands, as their NAA used to ban it before 201
Anyway, your pics were done in a twin, which changes everything.
AFAIK, over London Eye you will need twin to legally fly it and get ATC clearance…over City Airport, you can fly in SEP, it’s Cub & Mooney in those pictures 
Presumably the route under discussion is from the banbury vrp along the river valley, just west of rw09 threshold then directly south out of the CTR?? I’d say there is quite a bit of green down there, plus an actual runway, if it should go quiet up front…
There are not that many landing options south of City CTR on the southern bank (Biggin Hill has one of the scariest ILS when it comes to single engine failures, one does not notice it in IMC but in VMC, it does not look like good “situation d’avenir”) but yes plenty of choices on northern bank: the route Banbury-LCY-QE2 bridge has plenty of options including one “invisible airport”
PS: my guess is that 10million of people drink from Banbury reservoir every day, I think people in SEP should stay away from that VRP due to liabilities from environmental risks…
