The new head of communications to the prime minister of the United Kingdom used to dress up as a chicken and heckle Tory politicians, his former employer has said.

Lee Cain, who has been appointed as Boris Johnson’s chief spin doctor after serving as his press aide in the Foreign Office and during his successful Conservative party leadership campaign, was previously a Fleet Street journalist.

The Daily Mirror reported that it had deployed him in 2010 as the notorious Mirror Chicken, who was known for turning up at public appearances by Tory MPs and ridiculing them. It said Cain “taunted David Cameron and his Tory chums as they ducked questions in the run-up to the 2010 general election”.

Lee Cain after being appointed as Boris Johnson’s chief spin doctor. Photograph: Ben Cawthra/LNP

The paper said Cain was inside the costume in a picture it published from 2010 showing someone wearing a chicken outfit and Daily Mirror T-shirt outside a polling station with Cameron and his wife Samantha. Cameron went on to form a coalition government in a hung parliament.

The Daily Mirror quoted a former colleague as saying: “Lee was a great Mirror Chicken. He attacked the role with real zeal and great passion. The news desk were so impressed with his work he was used on a number of occasions.

“I vividly remember him coming to the newsroom and prancing around still in his full outfit like a rooster. It’s hard to believe a man with his past of taunting the cowardly Tories is now such a powerful figure inside No 10.”

As director of communications, Cain will be responsible for determining the Conservative government’s message in public.

Before working for Johnson, he was the head of broadcast for the Vote Leave campaign and had jobs with the government, including at No 10, before joining Johnson at the Foreign Office.