Sudan's political parties accused each other of widespread fraud and intimidation as voters began to register for the oil-producing state's first multi-party elections in 24 years. The reports came along with evidence of a growing rift between the two main parties in the country's coalition government, who fought each other in a two-decade civil war that ended in a faltering 2005 peace deal. Opposition political party monitors told Reuters they had evidence of intimidation, buying of votes and other irregularities by Sudan's dominant National Congress Party (NCP), headed by President Omar Hassan Al-Bashir. The NCP dismissed the allegations and accused its junior coalition partner, the former southern rebel Sudan People's Liberation Movement (SPLM), of trying to sabotage the election, saying NCP supporters had been tortured in the south. The SPLM and 20 opposition parties have threatened to boycott the elections if a long overdue package of democratic laws is not passed. They walked out of parliament last month. Bickering between the NCP and SPLM boiled over at a UN-sponsored meeting last week with witnesses saying relations were at their worst since the 2005 deal shared wealth and power in Africa's largest state. The 2005 Comprehensive Peace Agreement created the coalition government and gave the south a vote on independence in 2011. SPLM head Salva Kiir made his first public call for secession a week ago. US Sudan envoy Scott Gration has failed to persuade the former enemies to reach a resolution after extending last week's trip to the country to hold three days of intensive talks. “The (NCP) are using government resources for their campaign,” said opposition Umma Party official Mariam Al-Mahdi. She said her observers had seen many cases of faked papers and other fraud. “We are going to double up efforts in the coming week to collect this (evidence),” she said.