The Competition Commission's inquiry regarding the bidding war for Safeway's will now run far wider than previously anticipated.

In a letter to the four interested parties the commission stated its plans to use a wider market definition than used on the report into the sector in 2000.

Then it looked into stores of more than 1,400 square feet with a focus on the grocery market. Under this study it will look at all parts of the market, including convenience stores. It will also look at the affect of internet shopping and whether any proposed takeover could result in an increase in petrol prices.

The announcement follows chief executive of the Big Food Group Bill Grimsey's warnings that any takeover of Safeway by any of its larger rivals would push independent neighbourhood grocery shops out of business.

Grimsey said: 'Ten years ago families would use Sunday to go to the park or visit a museum but now they feed their kids in the cafeteria of a big supermarket. People used to pop to the local shop but I can see the end of the independent corner shop unless the commission acts.' Observers have warned that the detailed nature of the commission's issues may cause it to struggle in meeting the deadline of August 12 for giving its recommendation to the government.