Fifty lines have been added to Spar's own label range, including new heat-to-eat pasta dishes, smoothies, pasta salads and sandwich ranges.
One hundred own-label lines have been reformulated to make what Spar called "significant improvements to product quality".
Its standard own-label packaging has also been redesigned to closely resemble the new Our Very Own range to create "a coherent theme", while a further 15 Extra Value lines have been added to the 20 launched in February.
Spar is backing the launch with a £5m advertising campaign over the next year that will focus solely on own label.
Two 30-second TV adverts featuring computer-generated graphics will air in July, one focusing on barbecues and the other on lunchtime eating. Both will be backed by press ads.
"Sixty-two percent of consumers are more likely to buy own label this year than last year so the opportunity is huge," Spar UK marketing director Susan Darbyshire told The Grocer.
"Our customers are telling us they are not seeing a big enough range of own brands and we can now start to change that."