There is a media commentator (Andrew Napolitano) in the USA who has solved the mystery of who was spying on Trump during the election. Apparently it was GCHQ after being asked to by Obama. If it had remained just a commentator on Fox News which is well known for letting kooks, weirdos, and the generally insane spout all sorts of garbage, that would have been it.
But Sean Spicer then repeated the claims in a White House briefing.
And GCHQ have denied it.
But can we believe them? In this case almost certainly.
There is a very long standing convention within British intelligence agencies of neither confirming nor denying any action. Refusing to comment no matter how embarrassing is better than being caught in a lie, so the extremely unusual denial by GCHQ is believable because it is so unusual. But there’s more.
Firstly, Obama as president didn’t have the phone number of GCHQ (which is after all a British agency). A request from the president directly to GCHQ would probably be (and should be) answered with something along the lines of “Wrong number pal”. If he wanted to make a surveillance request it would go to the NSA who would then make an inter-agency request to GCHQ.
Which would of course result in a very secret paper-trail.
And if the request did make it through to GCHQ, the only surveillance data they are likely to have access to is international data (phone calls, Internet, etc) from Trump Tower to places abroad (with probably particularly good capture rates when passing through Europe). Which may well be of interest, but to actually put surveillance equipment inside Trump Tower?
That’s the job of a domestic intelligence agency, and whilst GCHQ could get involved in such an operation on foreign soil (and probably have), it is exceptionally unlikely in this case because it would put the intelligence co-operation agreements between the US and the UK at risk.
Whilst believing statements of an intelligence agency is a risky business, in this case it is probably true that GCHQ had nothing to do with any supposed surveillance of Trump Towers given the number of reasons why GCHQ wouldn’t be involved.