Her latest task, given to her by Prime Minister David Cameron, is considerably more complex than any she has tackled before: cut down on soaring shop vacancy rates, boost the number of small independent retailers and promote the creation of town centres "we can all be proud of".
A few have questioned whether she is the right candidate to take on the job, noting the chequered results from other government initiatives fronted by celebrity "tsars". But the appeal of Portas is obvious and less than four days after opening her website to comments on the independent review, more than 600 people had posted their thoughts – more than a similar appeal from the Department for Business, Innovation and Skills (BIS).
The self-styled "Queen of Shops" hopes she can transform the high street, though her battleground will not include Scotland where industry leaders are hoping to launch their own assault on the ailing state of town centre retailing. Leigh Sparks, professor of retail studies at the University of Stirling's school of management, says of Portas: "She has got a retail background, and she is well-known for what she has done on television, but there are a lot of technical details, such as rental rates and their impact on business rates and so forth, which make this quite a complex area."
Portas will report back to BIS this autumn but any recommendations she comes up with will not apply north of the Border. Leaders in Scotland's retailing industry are therefore pushing for the establishment of a retail policy framework by Holyrood, which they envisage including a town and city centre high street review similar to that which Portas is leading.
While some suggest a Portas-style appointment would benefit the Scottish effort, leaders are adamant that the country must devise bespoke solutions for problems particular to Scotland.
Fiona Moriarty, director of the Scottish Retail Consortium, says government and retailers need to "take ideas from a whole different rage of areas. Scotland's high streets and Scotland's towns and cities are very different from those down south, and what we need to develop up here is an integrated action plan that takes into account our specific circumstances."
Town centre vacancy rates across the UK have more than doubled during the past two years to 14.6 per cent as retailers have battled against the combined onslaught of the recession, the proliferation of out-of-town developments and the rise of online shopping. In some parts of London, the figure is more than double that while hard-hit English towns such as Margate are sitting with more than 37 per cent of their shops empty.
According to figures from retail research group, Local Data Company, Scotland as a whole is faring somewhat better with an overall vacancy rate of slightly more than 12 per cent. Its three major cities of Aberdeen, Edinburgh and Glasgow have vacancy rates of 13.4, 11.4 and 17.8 per cent respectively.
Glasgow in particular illustrates what Matthew Hopkinson of Local Data Company describes as the "dartboard" of city centre performance, with retailing in prime central locations holding up well. In Glasgow's case, this is represented by the so-called "style mile", where vacancy rates are running at about 11 per cent.
But secondary locations outside the centre are feeling more of the impact. Stuart Patrick, chief executive of Glasgow Chamber of Commerce, admits the picture is mixed but adds that long-term retail property investors are still coming into the city.
"Obviously the impact of the recession has been long and drawn-out – you get little spurts of recovery followed by periods where shoppers decide to put their money back in their pockets or purses," Patrick says.
The high streets of smaller towns and cities vary, with mid-sized conurbations in the shadow of larger retailing destinations under serious threat. Paisley, for example, has a shop vacancy rate of 23.5 per cent as consumers have been drawn away by the nearby Silverburn and Braehead shopping centres.
More remote locations can fare better as there is no immediate alternative to the local high street.
"With geographical remoteness you get a certain resilience, unless a major out-of-town development opens up, in which case you have two destinations vying for the same customers," Hopkinson says.
Aberdeen city centre manager Tom Moore says doomsday has come for some smaller town centres, which he pronounced as "already dead". He advocates swift action before contagion spreads. "The middle towns and smaller towns, what has happened there has started to leak into the city centres," Moore says.
There is a degree of evidence of this in Edinburgh, though the exact extent is difficult to quantify, given the recent disruptions caused by the city's tram project.
Graham Birse, deputy chief executive of Edinburgh Chamber of Commerce, says: "It is a matter of concern that the success of retailing in Edinburgh city centre has dropped from second to ninth in a period of about ten years."
He is also concerned about the so-called "Tesco tax", which the SNP wants to levy upon large out-of-town retailers.
Portas has floated a similar suggestion, with the percentage taken away put back into developing local community high streets. The SNP has implied a similar strategy in Scotland, though some fear the money raised would be used to balance the government's books, rather than helping small retailers.
"People would be more comfortable if that commitment was solidified," Birse said.
With myriad factors impacting high street retailers, it will take more than a celebrity campaign and a crash-course on customer service to arrest the decline.
"We have got to re-think the town centre – what size it is, what shape it is," says Sparks of the University of Stirling. "The physical scale of what we have now was made for the 1950s, and the way we live has changed dramatically since then."