Tesco has raised the price of more than 1,000 items in two weeks, including household staples such as pasta, rice and cheese.

The supermarket, according to internal documents uncovered by the Press Association, has raised the price of many own-brand products as well as big brands.

According to the files, during the first two weeks of July, prices were put up by an average of 11 per cent.

A five-pack of bananas has gone up 11 per cent from 90p to £1; own brand farfalle, macaroni and linguine pasta have all risen 30 per cent from 50p a pack to 65p; seedless strawberry jam is up 23 per cent to 92p and iceberg lettuces are up 17 per cent at 60p each.

The highest price rise was for Merchant Gourmet puy lentils, up from £1.42 to £3.60 a pack - a rise of 152 per cent.

The branded items with the biggest rises include Cathedral City Mild Cheddar up 57 per cent to £5.50 for 550 grams; 20-packs of Carlsberg lager up 33 per cent from £9 to £12; Ferrero Rocher chocolates up from £1 to £1.25 and a 5kg bag of Salaam basmati rice now £9 versus £7 previously - a rise of 29 per cent.

Of the top 50 price rises for the supermarket, 18 were own-brand products.

This squeeze is being felt across supermarkets, with a weak pound partly to blame as it costs more to import goods.

The prices of milk powder, potatoes and pork have all risen much faster than the official inflation figure of 2 per cent.

Tesco said the rises were due to cost pressures that were hitting the entire market, and pointed out that over the last three weeks prices were cut on 121 items by 24% on average, including own-brand coconut milk, down 55p to 90p, and Tesco frosted flakes cereal, down 20p to £1.

A spokesman said: "Over recent months, cost pressures have continued to build and impact the market.

"We've worked hard to offset these pressures, and focused on protecting our customers for as long as possible. But, like the wider market, we have had to reflect these pressures in the price of some products.

"For the majority of products that have increased in price over the last three weeks, we still beat or match the cheapest of the Big Four [Tesco, Sainsbury's, Asda and Morrisons]."

Price has been a major factor on the high street in recent years, driven by the rise and rise of discount supermarkets Aldi and Lidl.

Clive Black, retail analyst at Shore Capital, said: "The key journey that the UK supermarkets are on is to narrow the basket with the German discounters, who also move prices up and down. That is a key axis that shoppers undoubtedly notice."