Brendan Gleeson artfully channels Donald Trump in new 'The Comey Rule' trailer

The first full trailer for The Comey Rule has given a further glimpse at Brendan Gleeson’s transformation into a very convincing Donald Trump.

The Showtime two-part series sees the Irish actor star opposite Jeff Daniels as James Comey, with the programme based on the former FBI Director's book ‘A Higher Loyalty’.

In the trailer, Trump makes it clear loyalty is what he's after from Comey as he invites him for dinner at the White House following his presidential win.

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The drama charts the days before the election with the FBI having to go through Hillary Clinton's emails as well as dissecting potential Russian interference in the election.

It goes on to explore Trump and Comey's difficult relationship and the events that led to the latter's firing.

Viewers may notice while Gleeson does a stellar job as the reality show star turned world leader in the clips, he might not seem quite as garishly true to life.

Writer and director Billy Ray has said the programme sees "the first depiction ever of Donald Trump as a dramatic character" as opposed to the more cartoonish portrayals by Alec Baldwin on Saturday Night Live and the like.

Gleeson's appearance as Trump was toned down "everywhere that we could", Ray said.

"We made the contrast between the bags under his eyes and the orange skin softer than it actually is," he told Vanity Fair.

"We made the hair a little less cartoonish than it actually is. We made the suits fit a little bit better. We went out of our way to play fair because we felt we owed that to the public.”

Also captured in the trailer is Holly Hunter as former Acting Attorney General Sally Yates and Jennifer Ehle as Comey's wife Patrice.

Other stars of the series include Michael Kelly as former FBI Director Andrew McCabe, Kingsley Ben-Adir as President Obama while former National Intelligence Director James Clapper is portrayed by Jonathan Banks.

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While The Comey Rule was scheduled for release after the 3 November election, Ray protested the decision and it is now set to air on Showtime on 27 September with the second part screened the following night on 28 September.

It is not yet confirmed if the show will be made available to watch in the UK.