Its super unlikely to be a direct bribe, I think that much is fair to say. But I think viewed differently, the article is saying: Sunak's family has a tremendous interest in BP and Shell needing consulting services. Might this have an indirect effect on Sunak's willingness to legislate in ways that are highly likely to increase the amount of consulting services BP and Shell need?

Its not bribery, by any means, but I think its definitely noteworthy that these pressures / considerations may be involved