I presume you did actually read the article, Iains? If so you must have noticed this very significant sentence early on

The shorthand description of these as "laws from Brussels" is slightly misleading: the bureaucrats of the European Commission may well set many laws in motion by promulgating new directives; but they still need to be agreed by politicians from each member state, even if some are outvoted under the rules.

To answer the question posed in the article header. Yes, Britain is still a sovereign state.

DtG