Products grown or manufactured in the United Kingdom are set to make up 80 per cent of all items sold, the firm said, while 1,800 of the 2,600 brands will be under Jack's own label.
Tesco will open 10-15 Jack's stores across the United Kingdom over the next six months.
You've got to hand it to Dave Lewis - the decision to launch a new chain of budget stores is certainly ballsy.
The new chain is named after Jack Cohen, who founded Tesco 99 years ago, earning the nickname "Slasher Jack" for his "pile-it-high, sell-it-cheap" approach to retailing.
Matt Jeffers, managing director of Accenture Strategy, said: "We should expect to see more of the established players revisiting their store models, exploring mergers and acquisitions and building partnerships with competitors to head off intense competition and fight for customers".
Most of the stores will be converted from existing Tesco Metro stores.
We met John, who has worked at Tesco since 2007, in the carpark.
Tesco said the brand will "proudly support Britain's food producing communities" with eight out of 10 food and drink products at Jack's grown, reared or made in Britain. Some items did seem cheaper in Jack's: olives were 10p cheaper and Cherry Bakewell box 30p cheaper than in Tesco.
Jack's will also offer a range of limited-run general merchandise on a "when it's gone, it's gone" basis, similar to the special offer aisles found in the German discounters.
Tesco's foray into the discounter space follows close to a decade of consistent market leading sales growth from German brands Lidl and Aldi.
Tesco is Britain's grocery market leader with a share of 27.4%, while Aldi and Lidl have increased their combined share to 13.1%, according to the Kantar Worldpanel data.
Britain's "big four" grocers are trying to adapt to changing habits, including the declining popularity of big weekly shops and the growth of online shopping.
"It goes without saying, but Tesco will have to find a way to attract customers from the likes of Aldi, Lidl and Iceland, rather than convert existing Tesco customers into discount shoppers through brand association". (4278421) Launch of Jack's supermarket in Chatteris.
The ambition of Tesco is to launch in the next six months 10 to 15 stores Jack s in the United Kingdom, with an initial investment between 20 and 25 million pounds.