Starbucks and the other well known tax dodging companies? If we need more money to pay teachers properly, fund the nhs etc then surely if we supported retailers that pay UK tax it may help? I don't buy coffee much but I use Costa if I do, as it's part of a British company that pays tax.
I also shop in Sainsbury or Waitrose because they pay UK tax as opposed to Aldi and Lidl. I'm probably over simplifying this so please tell me if iabu!