I think that produce ought to be labelled, to show how much money is given to the actual growers - especially in the case of Fairly Traded produce.
It seems to me that many supermarkets take their opportunities to profit from others' misfortune , rather than letting them profit from their own hard work.... even in the case of Fairly Traded food, although in a different way.
For example, if there are two bunches of bananas.....
One may cost 80p for the bunch , and the grower might get 10p a kilo for the bananas, of which your bunch is maybe half.
With Fairly Traded bananas, they might be able to make a sustainable living through selling their produce for 60p a kilo.... but the supermarket might ramp up the price per bunch to £1.80 in order to get as much as they can out of the situation.
In this way they must surely also deter people from buying Fairly Traded produce as much as they might otherwise, or simply make it impossible for a lot of people to buy Fairly Traded produce regularly, by pricing them out.
Then, when few people buy their pricey producs they announce "well, there is little demand for this stuff" , and diminish their ranges of Fairly Traded produce, or drop them altogether, making it impossible even for those who want to buy it, and who can afford to do so, unable to do so, or left with a very limited selection on offer.
I think they would be ashamed if they were forced to expose their genuine pricing on labels, with direct comparison made there too on all produce, between comparable fairly traded and unfairly traded produce of it's kind, and might choose to drop their prices a bit and/or to be less mean about their profit-distribution structure.
which i think can only be a good thing !