Secretive artist Banksy has offered fans a free print if they vote against the Conservatives in a move which could land him in legal trouble.
The political graffitist posted on his website offering a print to voters in six Bristol area constituencies.
Applicants have to send him a ballot paper photo showing a vote against the Tories to get the limited edition work.
This would contravene laws designed to ensure votes remain secret, and could break rules against bribery.
The Conservatives declined to comment on the offer to voters in the Bristol North West, Bristol West, North Somerset, Thornbury, Kingswood and Filton constituencies in and around Banksy's home city.
He wrote: "Simply send in a photo of your ballot paper from polling day showing you voted against the Conservative candidate and this complimentary gift will be mailed to you."
The artwork, which he has also put on his Instagram page, reprises his well-known "girl with a balloon" motif, this time with a Union Jack in the balloon.
It will be released on 9 June, Banksy said on his website.
In a "lawyer's note" disclaimer, it adds: "This print is a souvenir piece of campaign material, it is in no way meant to influence the choices of the electorate, has no monetary value, is for amusement purposes only and is strictly not for re-sale.
"Terms and conditions to follow, postage not included."
Under Section 66 of the Representation of the People's Act it is a criminal offence to "induce a voter to display his ballot paper after he has marked it so as to make known to any person the name of the candidate for whom he has or has not voted".
It is also illegal to show the paper's unique identification number.
An Electoral Commission spokesman said: "Given the risk that someone taking a photo inside a polling station may be in breach of the law, whether intentionally or not, the commission's advice is against taking any photos inside polling stations."
Crimestoppers, which is working with the Electoral Commission to combat fraud, warns on its website: "It's illegal to offer money or gifts to voters, directly or indirectly, to get someone to vote a certain way, or not to vote at all."