Should Christians Boycott Tesco?

Stumbled across these comments by Sam Norton, reviewing the book 'Tescopoly' by Andrew Simms

"..(it's) a very thorough overview of the way in which Tesco functions
as a monopolist: one who has joined all the fields together until it is left
alone in the land. In many ways Tesco is simply a highly efficient corporation,
a (rare) example of world-class management in a British company. Yet it is
precisely the fact that it is so efficient, so effective in accomplishing its
aims, that it has had such dispiriting and impoverishing effects on our
communities.

Simms details the ways in which, through the use and abuse of its dominant
market position, Tesco actively harms those who supply it with goods, those who
work within its walls, and the communities within which it finds itself
operating.

For example, Tesco consistently pays its suppliers less than the industry
average, it is consistently late in paying invoices presented to it, especially
by the smallest suppliers, and, through the exercise of essentially bullying
tactics, it is able to 'borrow' more than £2bn a year from its suppliers for
free.

Internationally it suppresses wages in the third world and strips
communities of their dignity (I was astonished to read that in a farm in
Zimbabwe children are taught to sing "Tesco is our dear friend" in order to
impress the visiting potentates.)

My own concern is primarily with the impact on local communities in
England, and here Simms marshalls fascinating evidence. For every £1 spent in a
supermarket more than 90p leaves a local community; whereas the impact of a
'local box scheme' (ie locally produced and delivered vegetables) is quite the
reverse - for every £1 spent, £2.50 is generated in local wealth. In terms of
jobs, supermarkets undermine a community further: it takes £95,000 worth of
sales in a supermarket to sustain a single job, the figure for smaller stores is
£42,000.

Beyond this, the supermarkets, especially Tesco, support the use of casual
and unlicensed labour leading to what is effectively a modern form of serfdom.
Put simply the arrival of a supermarket chain in a town sucks money and
livelihoods away from the local area in order to agglomerate capital for
shareholders. Supermarkets impoverish communities in terms of income, social
life and common civility."

We have a local 'Tesco express', where at the moment we do a lot of our shopping, though we use a box system for veg, and a local dairy. Sam concludes that 'it is the duty of all Christians to boycott Tesco', though you'll need to read his whole piece to see how he reaches that conclusion.