Tesco chief executive Philip Clarke has warned that the era of cheap food is over as global demand grows.

Clarke told the Observer: “Over the long run I think food prices and the proportion of income spent on food may well be going up. Because of growing demand it is going to change. It is the basic law of supply and demand.”

Speaking in February, Clarke said that Tesco would source more of its produce in Britain and would seek to give a better deal for farmers in an attempt to restore brand trust in the UK.

The major grocers have historically pledged to keep food prices low amid rising commodity costs and demand for food increasing as the global population surges. But the grocery giant is now prepared to make widespread changes as public concern for for British agriculture grows.

Research conducted by Conlumino showed that almost two-thirds of consumers expect the price of supermarket food to rise over the next six months

Clarke‘s comments follow those of Waitrose managing director Mark Price, who has previously said food price inflation is inevitable.