The comedian and prankster - also known as his character creation Lee Nelson - followed up on a range of high-profile stunts in recent years by interrupting May's keynote speech at the Conservative Party's Autumn conference, taking place in Manchester.
During the US Presidential campaign last year, he gained international attention when interrupting Donald Trump to hand out Swastika-emblazoned golf balls, as the then-candidate appeared at one of his golfing retreats in Scotland.
Previous pranks also include breaking onto the stage during a Volkswagen event in Germany, in the wake of the diesel emissions scandal; and showering corruption scandal-hit FIFA President Sepp Blatter with fake money during a press conference in Switzerland.
Today's stunt saw the comic handing the beleaguered Prime Minister a fake P45, the HM Revenue & Customs form detailing a employee being fired from their job.
Urgent security questions are already being asked about how the comic was able to gain access to the conference centre and get to the very front of the audience in order to interrupt May's speech. Initial indications are that he was able to secure legitimate press accreditation.
Greater Manchester Police arrested Brodkin to "prevent a breach of the peace", and released him again shortly before 2pm without charge.
The fake P45 form was 'signed' by Boris Johnson, the Foreign Secretary who is widely thought to hope to replace May as Prime Minister and has been the subject of many newspaper headlines in recent weeks. Whilst being escorted from the conference centre by security after the incident, Brodkin insisted to reporters that Johnson had asked him this morning to deliver the form.
In the 'reason for termination' section of the form, Brodkin had written: "Neither strong or stable" and "We're a bit worried about Jezza" - thought to be a reference to Labour leader Jeremy Corbyn, and worry that May's apparent weakness after a bungled election earlier this year, could leave the door open to the far-left wing politician gaining power at a future General Election.
The form also specified May's gender as 'Robot'.
The comic - or more likely, his associates at talent management agency Avalon, as he had been arrested by police - posted on Twitter shortly after the incident:
A photographer from Press Association caught the following image of the form, as Brodkin handed it to May from just in front of the stage.
A close up of the P45 handed to Theresa May by @simonbrodkin Under reason for termination: "Neither strong or stable. We're a bit worried about Jezza." pic.twitter.com/Jzptoscvs3-- Stephen Jones (@SteveJonesPA) October 4, 2017
Press Association also published this video of the event:
Meanwhile, The Daily Telegraph published this video of Brodkin being escorted by security from the Manchester Central conference centre, and being questioned by reporters.
This video footage, also from Press Association, shows Simon Brodkin under arrest, being lead to a waiting police van before being driven away.
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