Bosses at Bingley-based clothing firm Damart are rubbing their hands in the big freeze – but not to keep warm.

The Arctic weather has sent sales soaring at the French-owned company famous for its thermal underwear favoured by the late Princess of Wales.

Sales have shot up by around 20 per cent compared with this time last year due to the cold spell, with online hits on its website soaring by 30 per cent.

Demand for warm clothing has boosted sales across Damart’s range – only ten per cent of which are thermal undies – such as overcoats, thermal lined boots, pyjamas and woollies.

Finance director Stuart Creeley confirmed the freezing weather had been good for business and feared stock could run out if the wintry blast continued for some time.

He said: “The extremely cold weather has benefited us and our sales are running about 20 per cent up year-on-year.

“Demand has risen for a wide range of products and if things carry on we could run out.

“Even though we manufacture some clothing, this is subject to lead times.”

Mr Creeley said most of the home-shopping firm’s 750 employees based in Bingley and Steeton had managed to get to work during the freeze and it had no major absenteeism, that has hit some firms.

He said: “Our staff are very loyal and hard working and have made every effort to get to work and enable us to cope with this surge in demand.”

In the trading quarter to September 2009 Damart’s UK sales rose by 17 per cent and had continued to grow at a similar rate in the second quarter, in spite of severe disruption from the recent postal strikes.

The firm is expected to achieve a turnover approaching £100m during the current financial year Last year Damart recruited around 40 more staff for its Bingley call centre, where around 400 people are based, and also transferred 70 jobs from Lancashire to a new production, mail and print centre at Steeton which houses about 350 people.

Damart’s managing director Andy Hill said: “The printing and mailing part of Damart’s business is crucial in attracting new customers and making sure existing ones are aware of all our new products.

“The move to Steeton and the new equipment will mean we will be able to further improve our service in this area.”

The company produces and mails-out more than 45 million catalogues and direct mail each year.

The latest move followed extensive improvements at the Steeton site which includes a state-of-the-art warehouse with upgraded machinery and equipment.