For those interested/concerned about ethical issues in the clothing industry:
I did a social accounting project which included a shadow/silent account focusing on the Arcadia Group for university last year. If anyone is particularly interested I can send you my project (it recieved a grade of 19/20 which is a very high first - everything is sourced so you can recheck any info you like)
I can say as far as the evidence goes, Primark is certainly no worse than any of the Arcadia-owned shops (includes Topshop, DP, Miss Selfridge, Burton etc.) or New Look among other shops, which are often far more expensive. None of the extra money you pay at these shops goes to the people who make the clothes - it does go to people with senior positions in the industry. H&M seem to have the best policy and control of producers wages and conditions including independent audits as evidence. Even places like M&S/Monsoon which you would expect to have more ethical practices are not reported to be any better.