The chain, which is vying with Sainsbury’s for the second biggest UK market share, will build 40 major superstores and well as a further 100 new supermarkets.

The expansion plan will also include 150 forecourt shops. Two-thirds will be in the south east, London, Cornwall and Devon.

The announcement came after Asda owner Wal-Mart chief executive Doug McMillon met Prime Minister David Cameron in an Asda at Clapham Junction in London on Monday.

McMillon said: “A seismic shift in the structure of the retail market is underway – not just in the UK – but right across the world.

“Asda recognised the change in its market and took early action to develop and implement a strategy that will see it grow.”

Asda has 577 shops in the UK, mostly in the north, and has about 17% national market share.

If planning can be obtained to deliver the ambitious programme of store openings up to 12,000 jobs will be created.