Anti-tax strike shuts Pakistan shops May 19 (Reuters) By Raja Asghar ISLAMABAD, May 19 (Reuters) - Retailers in major Pakistani cities shut their businesses at the start of a three-day strike on Friday in protest against the military government's plans to broaden the tax net as demanded by international donors. But the government said it would go ahead with its tax restructuring and Finance Minister Shaukat Aziz said negotiations were going on with traders to persuade them to comply. Traders said their strike was complete in major cities. Interior Minister Moinuddin Haider said 80 percent of shops were closed, partly because many have their weekly holiday on Friday. "The government will not step back," he told a news conference in Islamabad. "We are firm that we will not give in because we are right." The strike is an act of defiance against a military-led government which has made economic reform one of its key mandates, but the powerful business lobbies have faced down governments in the past. Religious leaders also called a strike urging Moslems to stay at home to press the government to implement Islamic laws and to protest the murder of a Sunni Moslem scholar, Maulana Yousuf Ludhianvi, who was gunned down on Thursday. The retailers are upset at the plan to impose a retail sales tax and conduct an army-led survey to trace tax evaders. "Talks are going on with different groups (of traders),"' Aziz told reporters in Islamabad hours after the start of the strike, which shut markets in Karachi, the Punjab provincial capital of Lahore and the Punjab industrial city of Faisalabad. But he did not give details. Most markets were also shut in the capital Islamabad and the nearby city of Rawalpindi, where the army's headquarters are based. DISSENT WITH IMF Similar protests by business groups have forced previous governments to back away from widening the tax net, creating dissent between Pakistan and the International Monetary Fund, which stalled a $1.56 billion loan programme last year after Pakistan failed to meet agreed targets. There is no broad-based retail sales tax in Pakistan and only one percent of the country's 135 million people pay income tax. Local newspapers reported on Friday that military ruler General Pervez Musharraf planned to go ahead with the tax survey, due to begin the last week of this month, a first step towards documenting the economy. "The government is fully committed to stabilise the economy and there would be no backtracking," Musharraf was quoted as saying by The News newspaper. But Umer Sailya, chairman of a powerful retailers' association, told reporters his members would not buckle under government pressure. "The IMF is a threat to our country, even people in Washington have launched a protest campaign against it," he said. The strike comes after an IMF mission arrived in Islamabad on Thursday to hold fresh loan talks on helping fund a three-year economic programme. The retailers said the tax opens them up to abuse by corrupt tax officials, concerns increased this week by the death of a businessman while being questioned by tax officials.