Pakistan's opposition Islamic alliance yesterday vowed to observe New Year's Day as a "black day" across the country if President Pervez Musharraf did not quit as army chief by December 31. The six-party Muttahida Majlis-e-Amal (MMA) may also call for a sit-in protest in Islamabad, the alliance's chief Qazi Hussain Ahmad told thousands of supporters here in the garrison city near the capital Islamabad. The rally was held amid a downpour after Musharraf categorically declared he would remain the army chief despite his pledge to abdicate the military post by the end of the year. "If Musharraf did not abide by his pledge to doff his military uniform by December 31, we will observe a countrywide black day of protest on 1st January," Ahmad told the crowd, many of whom carried umbrellas. "We will then consider giving a call to the people to march up to Islamabad for a sit-in protest," he said. It was the fourth rally staged by the MMA in major Pakistani cities over the past one month to muster support against Musharraf. Cricket hero-turned politician Imran Khan and local leaders of Pakistan People's Party of former prime ministers Benazir Bhutto and Pakistan Muslim League of ex-premier Nawaz Sharif also attended the MMA rally, joining in criticism of Musharraf's economic and foreign policies and blaming his government for rising prices. Musharraf in an interview with domestic Sindhi language television channel KTN on Friday said: "I will remain in uniform." Musharraf said that his decision was in the interests of political stability and national solidarity. **PHOTO CAPTION*** Pervez Musharraf.