Economists were today expecting a further slide in inflation after a fall in the cost of food and petrol.

The underlying rate of inflation - which excludes mortgage interest payments - slid from 2.3 per cent to 1.8 per cent in May and another dip is forecast for June.

Most economists are predicting the Office for National Statistics will unveil a fall of around 0.1 per cent.

That will take inflation perilously close to the key 1.5 per cent level, when the Bank of England is required to write an explanatory letter to the Chancellor.

But John Butler, economist at HSBC, said: "June should prove to be the trough in inflation."

Weaker petrol and food prices are expected to be behind the dip.