A mix-up with dates means actor Martin Clunes will not now be leading a Remembrance celebration to honour the eight million horses and one million dogs who served in the First World War.

The Purple Poppy Celebration starts at 3pm in Brewery Square in Dorchester this Sunday, and the public are being encouraged to bring their dogs along.

But it has emerged that Martin Clunes is already committed elsewhere and won’t be able to attend.

The event, which as well as honouring the sacrifice animals have made in conflicts around the world was also a chance to support two charities – TheHorseCourse and Pawsome Pensions.

Volunteers have been busy all year knitting purple poppies to sell at the event and in local shops.

TheHorseCourse CEO Harriet Laurie, from Askerswell, said: “We are really sorry to let fans of Martin’s down. It was our mistake that we messed up the dates. Martin is our patron and always more than willing to help us when he can but he can’t be in two places at once.

“We are still going ahead with the event and Martin says he’ll be there with us in spirit."

She added: “We will be selling hand-knitted purple poppies knitted by a small army of knitters and crocheters recruited by my dear old mum. They have made a collar for the bronze horse in Dorchester covered in purple poppies to commemorate the horses and dogs who died in service. There will be a celebration there on Sunday November 10 and the purple poppies our supporters have made will be sold to raise money for us and for Pawsome Pensions.”

Horses working at the mental health charity, TheHorseCourse, help troubled people from the age of eight upwards improve their mental health when talking therapies aren’t working.

The other charity Pawsome Pensions provides financial assistance for the welfare of dogs retired from the Police and Fire Services of Dorset, Devon and Cornwall.

The charity raises money to help pay for veterinary bills for the retired working dogs.

Martin Clunes has been a patron of TheHorseCourse from its beginnings in 2010.

He is still an enthusiastic supporter now the charity has moved to premises in Weymouth and expanded to work in the community with people suffering from a wide range of problems from anxiety, depression, autism, ADHD and addiction to victims of domestic abuse, bullying, neglect or PTSD.