The TV retail expert has recommended a range of planning policy incentives along with a new tax on car parks in out-of-town malls, as well as free parking in town centres to lure shoppers back to the high street.
Her Government-commissioned review sets out 28 recommendations to breathe new life into Britain's ailing high streets. She also proposes an annual national market day where budding entrepreneurs can try their hand at running a retail business. Marks & Spencer started as a market stall.
Portas said: "I don't want to live in a Britain that doesn't care about community. And I believe that our high streets are a really important part of pulling people together in a way that a supermarket or shopping mall, however convenient, however entertaining and however slick, just never can."
More than one in seven shops is empty, figures from the Local Data Centre showed in September. Vacancy rates have doubled in the last two years.
The government will publish its response next spring.