Police are reviewing claims of election fraud they have received relating to “concerns around marketing material”.
It comes after the Conservative candidate for High Peak in Derbyshire, Robert Largan, put out a social media post on Saturday in red Labour colours saying “Labour for Largan”.
He also put out a social media post, using the colours of Reform UK, with the slogan “Reform for Robert”.
The Conservative Party said: “The materials clearly carry imprints, as required by electoral law.”
Mr Largan captioned the former post saying that: “So many local Labour voters have told me they’re going to vote for me, because they want to keep me as their local MP.
“There have been so many that I’m launching a new Labour for Largan club.”
At the bottom of the red graphic, the advert says it is promoted by the Conservative Party.
The BBC understands Robert Largan has not been contacted by Derbyshire Police, which has not confirmed if his advertisement is the subject of the review.
A spokesman for Mr Largan said he had done nothing wrong.
“As Mr Largan’s social media posts and website make abundantly clear, large numbers of traditional Labour voters have been contacting him to tell him they plan to vote for him, despite him being a Conservative candidate,” he said.
“The same goes for Reform supporters – this is because of Mr Largan’s strong record of delivery in the High Peak.
“Therefore, supporters clubs of traditional Labour and Reform voters have been set up, to allow people to tell Mr Largan that they’re supporting him.
“These are called Labour for Largan and Reform for Robert. Such supporters’ clubs are not a new phenomenon.”
A full lists of candidates standing in High Peak at the general election will be released on Friday.
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