Street artist Banksy has had to withdraw his offer of a free print if they vote against the Conservatives in the general election after the Electoral Commission warned the offer “would invalidate the election result”.

The print he planned to give away was based on his Girl with a Balloon artwork, but what was previously a red heart-shaped balloon had been replaced with a Union Jack flag pattern.

Last weekend, the anonymous artist posted on his website asking voters in six Bristol-area constituencies to send him a photo of their ballot paper proving that they voted against the Conservatives to receive a limited-edition work. But Banksy has since retracted this offer, as Avon and Somerset Police received complaints and released this statement: “It is a criminal offence under the Representation of People Act 1983 for any voter to accept or agree to accept a gift or similar in return for voting or refraining from voting. Any person participating in an offer to receive a gift is at risk of being prosecuted.”

The UK General Election of 2017 will take place this Thursday, 8th June. To find your nearest polling station, head here.