An artist is considering legal action after the Conservative party used his cartoon to mock Andy Burnham.

Stanley Chow, a Manchester-based illustrator who works for the New Yorker magazine, created a cartoon of the prime minister for campaign material in the Makerfield byelection earlier in June.

At the Conservative conference this weekend, party workers handed out water bottles to journalists with the slogan "bottler Burnham" above Chow's cartoon.

He told the Guardian that the Conservatives did not ask permission before using his image: "I am taking legal advice, I may take legal action. It is copyright infringement, they are stealing my artwork to use for their own purposes.

"An institution like the Tory party – there is no excuse for them not to do their diligence, and find out the rules of copyright. It's amazing how it got signed off – that really disappoints me."

Chow first realised the cartoon was being used while watching Sky News. The presenters held the water bottles up to the camera and laughed at the joke slogan.

"I was more shocked really," Chow said. "When it appeared up on Sky News they were having a laugh and a joke about it, I thought, hang on, they have done this without telling me? I am peeved."

Chow said he had written to the Tories asking for an explanation but had not heard back. "It would be nice to get an apology out of them at some point."

Chow was also not a fan of the "bottler Burnham" joke: "It is very childish too, I think they should grow up."

He has also locked horns with Reform UK, which used his cartoon in an attack advert on social media aimed at the prime minister. It was deployed for an anti-immigration message – a stance the artist does not endorse.

Colin Bell, a partner at the law firm Brabners, said: "This is a clear case of copyright infringement. It's important because an artists' work, created with care and intention, has been used and edited without permission and without acknowledgment or remuneration.

"That's not acceptable. Stan is entitled to an injunction – or undertakings to cease and desist and take down the infringing works – compensation and a public apology.

"We're advising Stan in his pursuit of this claim to secure redress and to make clear that artists' work, rights and reputations cannot be treated in this way without consent, including as leverage or collateral in political campaigns."

The Conservative party has been contacted for comment.