Fire fighters had to be called in to the firm’s yard in Evesham in the early hours of Easter Monday to tackle the fire, which engulfed five machines. It took more than 2 hours to tackle the blaze using three large fire hoses and foam.

Sean Witherford, managing director of Jet, said: “It’s very clear the police see it as arson. It looks like whoever did it used diesel and straw to start the blaze.

“This is the fifth time we have been hit since 2005, we suffered four other fires at our Tetlaws business in Newton Abbott.”

To replace the damaged equipment, which included big 2m and 1.5 m road milling plant, would cost over £1m.

Witherford said: “In total we’ve probably lost about £2m of plant across the group. It’s really hitting us hard because our insurance premiums are rocketing.

“Thankfully we have a large fleet of 24 machines, with a little understanding from our customers we are managing to cover all the jobs.

“We’ve been really busy of late and this is a real blow.”