Clinton Cards is heading for a High Court showdown with an advertising agency next month in a dispute over its online florist service Clinton Cards fresh flowers.

Martin Tait Redheads (MTR), based in Newcastle upon Tyne, alleges that the greeting cards retailer stole its idea for a florist service.

MTR claims that it approached the UK’s largest specialist card retailer with a proposal for an online florist service. The two companies signed an exclusivity and confidentiality agreement, but the joint venture never happened.

However, three years ago, Clinton’s launched an online flower delivery service without MTR. Clinton is being sued for more than£300,000 in the long-running legal dispute. Clinton’s managing director Clinton Lewin declined to comment on the specific details of the case, but denied any of the allegations made against the retailer. MTR were unavailable for comment.

Clinton’s customers can choose from bouquets starting at£22 and items such as champagne, which can be delivered within 24 hours.

Ahead of its preliminary full-year results next week, Lewin said that the retailer aims to transform its shop portfolio next year. He said: “We’ve been experimenting with a new look for Clinton Cards and are pleased with how it’s going. We will continue to make our products more enticing, but want to put greater temptation on the high street.” The retailer relaunched its transactional web site this week, which Lewin said will be easier to navigate, with more products.