Seems a bit off point, but, true, the evidence is emerging of such. We have FBI and DoJ fingerprints already anyway. Vachel Lindsay well addressed the GCHG complicity - circumstantially.
Britain's GCHQ Denies 'Ridiculous' Claim It Helped Wiretap Trump
NBC - Mar.17.2017
GCHQ 'told US security services about meetings between Donald Trump's team and Russia'
telegraph.co.uk - 13 April 2017
A source close to UK intelligence said that the listening post had become aware at the end of 2015 of possible "interactions" and that this information was then sent across the Atlantic.
British spies were first to spot Trump team's links with Russia
The Guardian - 13 Apr 2017
Report: British spies first spotted Trump-Russia links in 2015
The Hill - 04/13/17
British intelligence passed Trump associates' talks with Russian on to US counterparts
CNNPolitics - April 14, 2017
I just copied in case there was some bit of utility in it, I’m really pretty dumb...