Two former army doctors have taken their campaign against what they call an “unfair dementia tax” to Westminster.

Dr Michael Staunton and his wife, Dr Avril Staunton, from Bridgwater, Somerset, are calling for the scrapping of a VAT rule that adds 20% to the cost of dementia day care at Exeter-based social enterprise The Filo Project.

Avril Staunton, who was diagnosed with posterior cortical atrophy at just 60, hand-delivered an open letter signed by 150 supporters.

A government spokesperson said Britain was leading dementia treatment by funding research and ensuring new effective, affordable treatments are introduced safely and quickly.

According to the Filo Project, unlike other permanent disabilities dementia care is not free on the NHS, leaving families to foot the bill.

The Filo Project provides small group care days for people with early to moderate dementia.

The project says because it operates as a Community Interest Company, it must charge VAT on its services and that means families pay an extra £3,120 a year if they attend twice weekly. Since 2014, it says clients have paid more than £500,000 in VAT.

Spokesperson Libby Price said “essential dementia care” should not be considered a “taxable luxury service”.

“For many families it means choosing between their loved one receiving care, and eating or heating,” she said.

Dr Michael Staunton said: “If Avril had a different permanent disability, we wouldn’t have to pay VAT on her care or it would be paid for by the state.

“The Filo Project is a life saver to me and many other family carers. It’s not a matter of convenience, it’s a lifeline in giving families respite.”

A government spokesperson said: “We are putting Britain at the forefront of transforming treatment for dementia through continuing to fund high-quality research into the disease and ensuring new clinically and cost-effective treatments are rolled out in a safe and timely way.”