One in five consumers said they "punished" companies they believed were socially irresponsible by not shopping with them, according to a new study.
A survey of 1,500 people by the Fairtrade Foundation also found that one in three shoppers were likely to give business to companies for being socially responsible.
Almost nine out of 10 of those questioned said they expected workers in developing countries to receive fair pay and conditions.
Women were more likely to be motivated by feelings of doing good when they bought products, said the report, adding that the Fairtrade mark came top as the most trusted certification label.
Cheryl Sloan, marketing director of the Fairtrade Foundation, said: "It is very encouraging that UK consumers continue to be very receptive to Fairtrade and show high levels of awareness, familiarity and purchasing.
"Fairtrade is clearly no longer a fringe sector within retail, but companies should also take note that shoppers are prepared to send a very strong message to them about their global accountability."
More than half of those surveyed expressed concern about human rights, poverty in developing countries and worker exploitation.