Times are tough enough for independent traders without getting a tax bill out of the blue for nearly £500 - for having air-conditioning.

That's what Debbie Hellier is having to fork out as businesses get clobbered for a business rate premium which they say is greedy and unfair. The demands come from Gravesham council, which collects the rates on behalf of the Revenue.

The traders have come forward to highlight the dent into their hard-pressed profits as part of the Gravesend Messenger's campaign to support town centre shops, pubs and eating places.

The business tax centres on places who have air-conditioning on their premises to keep customers warm in winter and cool in summer.

They are being taxed just for having air-conditioning, even though they pay separately for the energy it uses. The tax has its roots in the Domesday Book, the first comprehensive record of property for tax purposes.

Air-conditioning is among items and facilities listed for tax purposes as plant and machinery.

Debbie Hellier, owner of Crumbs sandwich bar and restaurant in Gravesend’s King Street, said: “I took over this business two years ago and just recently I’ve been hit with a back payment for 18 months – a tax of £469.05 for having air-conditioning.

“Here we are a family business, which I run with the help of my husband and daughter, Amie, trying to make our customers comfortable, and we get this unfair bill.

“Most businesses in Gravesend are facing challenging times, and this sort of outdated tax seems to me to be at odds with the government’s aim of trying to support and help us grow.”

It’s the same along the road at Fisherman’s Catch restaurant in New Road, where owner Dev Randhawa says he is furious over his latest tax bill for using air-conditioning.

He showed the Messenger his business rate statements, revealing the charge had jumped from £118 in 2013/14 to a whopping £241 this year. Dev runs his restaurant with his wife, Tersam, and son, Gurjit. They have operated there for 25 years.

“How can the taxman regard air-conditioning for customer comfort as taxable? It is just plain greedy.

“The charge is clearly unacceptable. We’re paying for past government mistakes with banks nearly going broke, and we’ve ended up paying the bill. Despite tough economic challenges, we continue to work hard for our tremendously loyal customers, without whose support we would not survive.”

A spokesman for the Treasury’s Valuation Office Agency said traders should get in touch.

He said: “We cannot comment on individual cases. Air-conditioning is generally regarded as rateable, and is therefore reflected in the rateable value.

“If a ratepayer thinks their rateable value is not a fair reflection of the rental value, they should contact us to discuss it. Ratepayers can find out more about their valuation, including details we have for their property, at www.voa.gov.uk/valuation.”