Governments in the Ivory Coast and Gabon will be tested on Sunday in elections that reflect growing demands for multiparty democracy in sub-Saharan Africa. The Ivory Coast's octagenarian President Felix Houphouet-Boigny faces an opponent for the first time since independence from France in 1960. In Gabon, President Omar Bongo's Democratic Party - with 22 years of autocratic rule - is being challenged by several opposition parties in the last round of voting for the national assembly. The ruling parties are favored in both elections, but their supporters concede that it no longer will be possible to shut opposition parties out of the system. All but a handful of black Africa's nations were one-party states at the beginning of the year. When Communist regimes started to fall in East Europe, Gabon's state-controlled newspaper The Union commented: ``The great winds carrying democracy ... that have triumphed in the countries of Eastern Europe will not shake the coconut trees in Africa.'' Within weeks, one African country after another was hit by demonstrations demanding change. As in Eastern Europe, the collapse of economies was a major cause of Africans' dissatisfaction. By now, at least 13 governments have said they accept multiparty democracy in principle: Angola, Benin, Cameroon, Cape Verde, Congo, Gabon, Guinea-Bissau, Ivory Coast, Mozambique, Sao Tome and Principe, Somalia, Zaire and Zambia. Some governments, including Kenya, Sierra Leone and the Central African Republic, have refused to concede any rights to opposition groups, equating criticism with treason. Although Houphouet-Boigny gave in to demands to legalize opposition parties following riots in February, his government has used every device at its command to block them. Opposition meetings were often banned or constrained by broad restrictions. Government-controlled television and radio rarely mentioned the opposition, except to accuse it of responsibility for damage caused during the riots. The media nightly broadcast lengthy reports on meetings of people who supported the president. After several demonstrations at the national television station, the opposition was granted 20 minutes nightly of air time, a concession made only two weeks before the voting. One night, the opposition broadcast was banned on grounds it contained lies. One government restriction may have backfired. Initially, it sought to encourage as many opposition groups to form as possible, diluting their strength. But only a week before the 10-day presidential campaign was opened, candidates were required to post the equivalent of an $80,000 bond. The bond would be forfeited if the candidate failed to gain at least 15 percent of the vote. Only one of the newly formed parties, the Ivorian Popular Front, was able to meet the demand. This reduced the election to a contest between Houphouet-Boigny and front leader Laurent Gbagbo, a 46-year-old history professor who had been jailed for two years for opposing the president. Although no opinion polls have been conducted, Gbagbo's party acknowledged it was having difficult building from its base of middle-class and educated Ivorians. It also lacked the staff of Houphouet-Boigny's Ivorian Democratic Party, whose control of the government for 30 years gives it broad leverage with the population. The opposition's main campaign theme has been that Houphouet-Boigny and his cronies have enriched themselves while the country's once wealthy economy has been brought near collapse. Ivorian officials said first returns from voting will be released Sunday night. Houphouet-Boigny, 85, Africa's longest-serving president, received 100 percent of the vote in 1985, according to the government. The situation is more complicated in Gabon, also a former French colony, where Bongo still has three years to serve as president. Even the legalization of opposition parties failed to stop unrest this year, and France was briefly forced to send in troops to evacuate Europeans from the oil center of Port Gentil. Bongo may have won some breathing space with the sharp increase in oil prices after the Iraqi invasion of Kuwait. The party of the president, who claimed 98 percent of the vote in the last presidential election, was winning 62 percent of the seats before the final round of voting Sunday.