An opposition leader in Equatorial Guinea on Tuesday called for the government to resign over its failure to release political prisoners, a promise made by President Teodoro Obiang Nguema."This government is unable to implement and respect the law - it must resign," said Andres Esono Ondo, the general secretary of the country's second largest opposition party Convergence for Social Democracy (CPDS).Obiang issued a decree granting what he described as a total amnesty on July 4 in a bid to smooth the way for a "national dialogue" between political leaders in the country.But on the second day of the talks, which opened in the absence of key opposition figures, none of the prisoners had been released, Esono Ondo said. The leading opposition, the Citizens for Innovation (CI) party, also said on Monday that none of its jailed members had been freed.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTER FOLLOW News24 Africa on Twitter and FacebookObiang, 76, has ruled the West African state since 1979, a tenure widely criticised for corruption and human rights abuses. "The government is perfectly legitimate and it is not at this forum that its future should be questioned," said Eugenio Nze Obiang, a spokesperson for the government. He also told AFP that "the government has instructed the prosecution... to contact all indicated judicial officials to free the beneficiaries of this amnesty."The five-day forum - the sixth such "dialogue" in Obiang's nearly 39 years in office - comes on the heels of an attempted coup last December and a crackdown on the opposition.Interior Minister Clemente Engonga Nguema Onguene has previously said the dialogue would discuss "issues such as democracy, human rights."The CI was banned in February and 21 of its members, including the party's sole MP, were subsequently sentenced to 30 years for "sedition, public disorder, attacks on authority and serious bodily harm."