Greggs admits it has been forced by soaring wheat costs to increase the price of some of its products.

Before July, the company paid about £103 per tonne but in the summer this rocketed to about £170. "Prices have since dropped slightly but not by as much as we expected," said chief executive Ken McMeikan. "We have increased the prices of some of our bread rolls, but only by a few pence."

The bakery chain had managed to avoid raising its retail prices until July, when it was hit by the large wheat price hikes, he said.

This week, Greggs reported total sales up 2.6%, with like-for-like growth of 0.5% in the 39 weeks to 2 October. It has opened 32 new shops this year so far, and expects the final total to be at the upper end of its forecast 50 to 60.

It has also completed 84 refurbishments, including 17 concept shops.