A spate of discounting has crushed profits at Thorntons, leaving the purveyor of Viennese truffles and chocolate bunnies set for its worst annual performance in more than a decade.

Although total sales inched up 1.3 per cent to £128.4m over the six months to January 10, pre-tax profit fell 39 per cent to £7.3m and the company cut its interim dividend by more than a third to 1.2p.