Following a military coup against Taya in August 2005, an amnesty in early September freed Haidallah from his sentence, along with more than a hundred others sentenced for political offenses. On December 27, 2006, Haidalla announced that he would be a candidate in the presidential election scheduled for March 11, 2007. He campaigned on a nationalist-Islamist platform, citing the struggle against poverty and slavery as priorities. On February 3, he gained the support of another registered presidential candidate, former opposition politician and prisoner under Ould Taya, Chbih Ould Cheikh Melainine, who dropped out of the race.