Five political parties in Equatorial Guinea, ruled by Africa's longest serving despot, signalled their willingness on Tuesday to take part in a national dialogue next month if their security was ensured.A former Spanish colony of 1.2 million people, awash with oil but mired in poverty and a reputation for corruption, Equatorial Guinea has been ruled with an iron fist by Teodoro Obiang Nguema since August 1979.Last month, the 76-year-old called for "dialogue and political interaction" in July and for the first time invited foreign observers to the talks.Francois Lounceny Fall, the UN Secretary General's Special Representative for Central Africa, said he will show up.The five political groups said in a joint statement that they were ready to participate if the talks "were held outside Equatorial Guinea (like in former colonial ruler Spain) or in Equatorial Guinea but with the backing, help, protection and security of the international community."They also called for a general amnesty before the process. The group includes the Party for Progress of veteran politician Severo Moto Nsa, who has been living in Spain since 1982 after being sentenced to 62 years over a failed 2004 alleged coup.Obiang had called on Guineans living abroad "to come home, to the country of our birth, to look for all-embracing, inclusive strategies."The offer also applies to those who are in exile, he indicated - "to all Equatorial Guineans who are dispersed in the diaspora for political reasons, for certain political crimes."The offer came after an attempted coup, in December, involving a group of men from Chad, the Central African Republic (CAR) and Sudan, according to the authorities.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTER FOLLOW News24 Africa on Twitter and FacebookThe operation was followed by the arrests of scores of opposition activists and the banning of their party, the Citizens for Innovation (CI). The last such dialogue was held in 2014 and five opposition parties were legalised after that.