It's not easy to say no to your parents when you have been used to obeying them your whole life, but it's time to make your own decisions. They may withdraw financial support or make it difficult for you to come home in the holidays but most likely, they will give in when they realise that you have made your decision either way. If they refuse to help you out financially, you will probably have to work part-time during term, and full-time in the holidays, but lots of students manage that. Better to have to work harder, but be independent and choose your own course in life, than to allow your family to make your decisions for you.