The U.K. interfered in the 2016 election by spying on the Trump campaign. The big question here is how did this information get leaked? And why now?
My money is on a remoaner who wishes to sabotage Britain’s relationship with the US in order to force Britain back into the embrace of the EU. There is a very large crossover between inveterate EUrophilia and anti-Americanism in the UK, and a similar crossover between pro-Ammericanism and anti-EU sentiment.
In my lifetime the U.K. has gone from an empire upon which the sun never set, to a country circling the proverbial drain... Based upon what is reported, this does not sound like a 'leak', but a deliberate dump.