Discount supermarket Aldi is set to plough £30million into new West Midlands stores as it continues to see middle-class shoppers defect.

The German company said it was planning to open at least four new stores in the region next year, creating 120 jobs, and revealed longer term plans to double stores in the Birmingham area.

Aldi Midlands regional managing director Marius Manolescu said: “If you take Birmingham and the surrounding areas, we have 19 stores and would like to double that at least. There are parts of the region where we have little or no representation, we would like to expand in those areas.”

Aldi has 69 Midlands stores and next year will add sites at Northfield, Birmingham, Dudley, Stourbridge and Stratford, continuing the rapid expansion drive put into action this year.

Between the end of October and November, Aldi opened four new Midlands stores including Sheldon and Maypole in Birmingham.

TNS data showed Aldi has been one of the winners in the flight to value brought by the economic downturn, hitting a new record in market share and achieving year-on-year growth of 25.4 per cent.

The discount chain has seen Midlands footfall increase 30 per cent in three months, with each store seeing approximately 3,000 new shoppers per month.

Aldi’s success has been such it has even spawned a convenient label for the economic phenomenon of shoppers trading down to cheaper suppliers.

Mr Manolescu said the grocer was not perturbed by its name being borrowed to coin the phrase “the Aldi effect”.

“What we were striving to do is give customers the best quality products at the lowest possible prices and if people want to relate our success and use it as a point of reference of course we are humbled by it.”

Mr Manolescu said over half of the store’s customers are from the social demographic ABC1.

“The economic downturn has provided an opportunity to attract new customers and keep them. The downturn gave them a jolt to try new markets,” he said. “In the Midlands I’m seeing over 150,000 new customers coming into our stores every week.”

An influx of customers from wealthier backgrounds has meant a change in the products being rung through the tills, said Mr Manolescu.

“Sales of fresh fruit and vegetables have doubled over a year and fresh meat and fish have performed very well too – for example sirloin steak and smoked salmon,” he said. “Also fine wines such as Chateauneuf du Pape and Sancerre are performing very well as a result of new social demographics being attracted to our stores.”

He added the prospect of recession had not had any effect on Christmas food spending to date in the Midlands.

“Some of the expensive products like the three-bird roast are selling very well – we are seeing people spend quite a significant amount of money.”

If Aldi has been a winner this month Tesco was revealed as one of the losers.

The UK’s biggest grocer posted its weakest UK sales performance since the last recession after a supermarket price war halved growth in the last quarter.

But defectors from Tesco helped Morrisons report an 8.1 per cent leap in its third-quarter sales thanks to the chain’s value ranges and cut-price deals.

The group said its efforts to keep shopping bills and fuel costs down had been “extremely popular”, with more than 700,000 new shoppers.