MPs are to campaign for the current Planning Bill to be rewritten to stop supermarkets from expanding without planning permission by building mezzanine floors inside existing stores.
After Asda almost doubled its floorspace at an out-of-town superstore, MPs held a meeting last week to agree a campaign to prevent supermarkets from exploiting this loophole in the planning law.
Asda, owned by US retailing giant Wal-Mart, plans to build extra floors in up to 40 other UK stores.
A spokesman for the supermarket group said: “We’re doing exactly what planners want, making more efficient use of the space we have in store without having to build large extensions taking up more land.”

Safeway could face criticism over directors’ two-year contracts and pensions at its annual meeting tomorrow.
Executive chairman David Webster, finance director Simon Laffin and group services director Richard Williams, have two-year contracts - not considered best practice by the company’s investors.
Chief executive Carlos Criado-Perez holds a 12-month contract but would receive £1.3m if he loses his job as a result of a takeover of the group.

The property arm of supermarket group Sainsbury is in line to be sold for £200m to one of three contenders - construction company Kier, private property group Miller and a consortium of Castlemore Securities, Standard Life and HBOS.
The property unit generates £15m in annual profit - about 2% of Sainsbury’s overall profit. Formed in 1993, the portfolio has 20 projects, mainly shopping centres including the brewery in Romford, Essex Lemon Quay in Truro, Cornwall and Cuckoo Bridge Retail Park in Dumfries.