WHO is Jonathan Pie? He’s the spoof TV reporter famous for rabid, left-wing rants that have gained him thousands of online followers. Imagine a mash-up of Alan Partridge/David Brent /Alexei Sayle/Ben Elton, and you’re almost there.

The real Jonathan Pie is actor and comedian Tom Walker, and it is credit to Walker’s acting ability that he is utterly convincing as a TV reporter, despite having no journalistic training. In fact, a spoof vlog he posted following the shock election of Donald Trump was picked up by US right-wing media outlet Breitbart as if it were genuine. Fake news indeed.

As the loftily liberal Pie, Walker rips into his lame victims with rottweiler ferocity. By the end of the 60-minute show, he’s practically salivating on the carcasses of Trump, Theresa May, Millennials and, you may be surprised to learn, liberal Guardian readers.

He is dazzling in his dynamic dissection of the enemy’s stupidity: likening Tory voters to flies being drawn to those blue “zapper” lights in restaurants, reminding us that we never learn the lessons from history; that’s why we keep voting Conservative.

Trump is an easy and irresistible target. Despite criticising the audience and young people for their addiction to mobile phones, Pie (whose @JonathanPieNews Twitter account has more than 90,000 followers) proceeds to poke fun at the President through a show-and-shame PowerPoint of some of his most crude and cretinous comments.

We learn that the President struggles with simple spellings and the use of the ellipsis, using four or more dots when three is all that is necessary, and has a weak spot for tweeting in the middle of the night, often making up policy on the hoof, creating headaches for his team the next day.

Theresa May is also lined up against the wall for a verbal assassination, the torrent of abuse as quickfire and devastating as ammunition from an automatic weapon.

He’s on pretty safe ground while Trump and Tory bashing – it’s a given that the audience will be mostly made up of fair-minded liberals (like Pie, but probably less foul-mouthed; his use of the F and C words make Gordon Ramsay sound like an amateur).

So it’s audacious of him to turn on these supporters and force them to reflect on quite how liberally minded they actually are. He tackles the tendency for people on the left to shut out and shout down opposition voices, dismissing disagreements with accusations of bigotry, racism, sexism and misogyny.

Again, his polemic is convincing and you genuinely believe it when he says what really irritates him is: “liberal people doing illiberal things in the name of liberalism”.

The format of the show is different from his three-minute YouTube films – and the better for it. The conceit is that he is making a pilot for a TV show. But Pie is probably too partisan and definitely too sweary for a TV show. Which is why you should catch him live if you can.