The powerful Muslim Brotherhood\'s candidate Mohammed Mursi warned Sunday against any attempt to tamper with Egypt\'s presidential poll this week as thousands of supporters rallied across the country on the last day of campaigning. The Islamist movement\'s presidential hopeful also told a mass rally in Cairo that he would not impose a \"theocracy\" if elected in the May 23 and 24 vote, the first since an uprising toppled president Hosni Mubarak last year. Mursi is trailing behind in polls, but surged in expatriate votes cast last week in diplomatic missions, according to Egyptian media reports. In the nighttime rally in Cairo, Mursi said anyone attempting to \"revert (back to the old regime) or forge the people\'s will\" would be \"trampled and burnt by popular anger\". Similar rallies took place in more than a dozen cities around the country. Mursi did not elaborate on who might forge the election, but vaguely mentioned loyalists of the former president. The military, which took charge after Mubarak\'s ouster, has pledged a fair election. Mursi said the military was still \"loved\" for not siding with Mubarak during the uprising that toppled the veteran strongman in February 2011. But he told them that their role in a new constitution \"must express the people\'s will\". The Brotherhood had clashed with the ruling generals after they refused to sack the government and allow the Islamist\'s political arm headed by Mursi, the Freedom and Justice Party, to appoint a new one. It accused the military of angling to remain in control even after a promised handover to the elected president by the end of June. The Freedom and Justice Party dominated parliamentary and senate elections that ended in February this year, but analysts say it has lost support after a lacklustre performance by its lawmakers. Sketchy polls taken by a government-funded think tank and the cabinet\'s research division show Mursi trailing behind moderate Islamist Abdel Moneim Abul Fotouh, former foreign minister Amr Mussa and ex-premier Ahmed Shafiq. Mursi lost the expatriate vote in most countries, but received a boost on Sunday after the consulate in the Saudi Arabian city of Jeddah announced that Mursi won with almost 27,000 votes, the official Al-Ahram newspaper reported. Most expatriate voters are registered in conservative Gulf countries and are expected to give Mursi a victory in the overseas vote. The full results for that vote have not been announced. But the number of eligible voters abroad -- roughly 600,000 -- is insignificant compared with the 50.4 million voters in the country.