Subway is jumping on the Veganuary bandwagon in the U.K. with a campaign to introduce its Meatless Meatball Marinara Sub—by pranking vegetarians.

The sandwich chain and agency Above & Beyond filmed a series of three live tastings, during which vegetarians were invited to try out the new Meatless Meatball Marinara Sub. However, during the tastings the host suddenly gets "confused" about whether or not they have in fact been given the meat version. Everyone starts to look horrified—but then they are quickly reassured by a Subway employee that they are in fact eating a meatless product.

Rather than scripting the tasting event and having it played out by actors, it was done for real. To direct, the team tapped Sam Cadman, co-creator of 1990s Channel 4 series "Trigger Happy TV," which specialized on pranks on real people.

"Doing it ‘for real’ with Sam, who alongside Dom Joly reinvented the TV prank genre for a whole generation, was equal parts exhilarating and terrifying," said David Billing, chief creative officer at Above+Beyond, in a statement. "You simply can’t predict what’s going to happen each time, and you definitely can’t simulate the kind of reaction that a real audience will have when things have seemingly gone horribly, horribly wrong.”

Al Gounder, Marketing Director at Subway, added, “Less than 1% of the UK identifies as vegan, so this campaign addresses the 42% who call themselves flexitarians, without excluding the 88% who identify as meat eaters. We’ve done something fresh and slightly anarchic that will disrupt all the ‘me too’ conversation in Veganuary and put the Meatless Meatball Marinara firmly on the map.”