German discount retailer Aldi opened its first four supermarkets in Switzerland on Thursday with the promise of a relentless expansion campaign.
The arrival of Aldi stores in Weinfelden and Amriswil is canton Thurgau, Altenrhein in St Gallen and Gebenstorf in Aargau will be followed by two more in the coming weeks with many others planned.
So far, Aldi has concentrated on the German-speaking area of Switzerland, including two sites inked in for development on the outskirts of Zurich.
But spokesman Sven Bradke told swissinfo that the discounter is already eyeing up more than 20 towns in the French and Italian-speaking parts of the country for expansion.
"We have started in the north of Switzerland because we know the region and saw good locations, but we will expand to the west and south," he said.
"We are not quite ready yet, but we will do our best to move as fast as possible."
Swiss supermarket chains Migros and Coop have already responded to the threat by introducing or expanding a branded range of discount products, while Denner strengthened its position by acquiring Pick Pay last month.
But Bradke said that he is unconcerned by the defensive strategies of Aldi's competitors.
"We are not worried at all. Coop and Migros only have a limited line of discounted products that cannot compare to our extensive range. We will just concentrate on ourselves," he said.
However, trade union Unia is unhappy with working conditions being offered by the German retailers.
Unia representatives handed out leaflets at the Weinfelden store opening ceremony that complained of low wages and an authoritarian regime that threatens dismissal for smoking in forbidden areas.
"We have good salaries and our people are very engaged in their work. They are highly motivated and that is most important," said Bradke in response.
Shoppers were out in force at the Weinfelden store, mainly attracted by the prospect of a bargain.
"I think that it is a good thing that Aldi have come to Switzerland," said Denise Meier. "Shopping used to be too expensive here and the Swiss supermarkets had it too good.
"It is good that people now have more choice and that prices are being forced down by the competition."
Weinfelden local Philipp Haffner was also positive about the arrival of the German store.
"I will come here to buy my basic shopping at good prices," he told swissinfo. "But I will still use my local butcher and go to other shops for the rest."
swissinfo, Matthew Allen in Weinfelden
Aldi will open two more stores in Pfäffikon, canton Zurich and Romanshorn, canton Thurgau in the next few weeks.
Sites in cantons Zurich, Uri, St Gallen, Appenzell Outer-Rhodes, Bern, Schwyz, Thurgau and Aargau have been identified for development in the near future.
Aldi projects the eventual expansion into some 23 towns and communities in the west and south of Switzerland.