A leading NGO has appealed to Delhities to call up chief minister Sahib Singh Verma on Friday to register their protest against his government's reported decision to scrap the ban on commercial vehicles older than 15 years. Calling for the novel "jam-their-phone lines to be heard" campaign, the Centre for Science and Environment said that on Friday, its volunteers will call the chief minister's office throughout the day to demand that he does not allow political aspirations of his party take precedence over their health.It asked Delhities to take up the campaign and call up Mr Sahib Singh Verma whenever they are free and as many times as they can between 9 am and 5 pm.