Dumb, Dumb! DUMB!!! Its probably just the UK version of porkbarrel politics.
If the UK was serious about a launch facility, they'd put one on Ascension Island. 7.5 deg south of the Equator, with 1000 miles of open ocean downrange to the east before you hit anywhere even minimally populated on the coast of Africa. Its already got a 2 mile long runway which was an emergency landing option for the space shuttle, and a deep water all weather harbour could be constructed in South East Bay with an adjacent launch site near Whale point. Of course it wont be cheap, but playing seriously in the national space game never is.
If the U.K. wanted to cheap-skate it, they'd move some decommissioned oil rigs from the North Sea for infrastructure platforms to 2.5 miles East of Gibraltar, in British territorial waters, with 270 miles of clear water to the east to the coast of Algeria, and contract with Elon Musk to moor SpaceX launch barges there.