From gruelling abattoir exposé Dominion to plant-based fitness paean The Game Changers, preaching to the choir has always been an issue in the burgeoning sub-genre of vegan documentaries. The same is partly true of new addition to the canon, I Could Never Go Vegan, though not for want of trying. From the off, this impassioned pro-plant proselytising from the Pickering Brothers (director Thomas and writer James) does its best to provide a gentle entry point to the weighty and ambitious subject matter it tackles. 

The film places affable everyman Thomas Pickering at its centre as he answers stock questions from meat-eaters with the forensic detail of a master’s thesis. The queries and asinine statements he faces will be instantly recognisable to most vegans (where do you get your protein from? Why is bacon too delicious to give up? Isn’t plant-based food disgusting?) but what the Pickerings do with them proves at points to be revelatory, providing the kind of joined-up thinking that’s missing from single-issue documentaries focusing on fitness or animal welfare.

Diffuse though it may initially appear, the Pickerings’ overarching approach pays dividends when they begin discussing animal welfare and ecology in brutal, precise and unflinching detail, sharing footage and statistics which are stomach-churning enough to turn a butcher vegan. Its final moments, which invert the idea of the circle of life by describing ecological and ethical horrors of animal slaughter, have a clarity of vision that even those in Camp Carnivore would struggle to refute. While meat-eaters are unlikely to flock towards this in their droves, its watertight case for a plant-based diet could convert flexitarians who give it their time.

I Could Never Go Vegan is in cinemas from Friday 19 April.