Dinesh Trivedi has refused to resign as Railways Minister till he receives orders in writing from his party chief, Mamata Banerjee. "Till the time the matter is absolutely clear, I have suggested I do not want to take anything verbal. For me, Parliament has more sanctity than anything. So, I suggested let Mamata write me a letter so that there is no confusion...I will perform my duty as a Railway Minister," Mr Trivedi told reporters in New Delhi today.