Guinean President Alpha Conde's party won more than two-thirds of the seats in legislative elections held last month that were boycotted by the main opposition, the country's electoral commission said.
The government had already declared victory in a referendum held the same day on changing the constitution, which opposition groups allege was a plot for Conde to extend his grip on power in the West African country.
Conde's ruling Rally of the Guinean People (RPG) won 79 of 114 seats in the National Assembly, the commission said Wednesday evening.
The March 22 vote was marred by violence, with scores of polling stations ransacked and, according to the opposition, dozens of people killed.
The United States and the European Union have cast doubt on the credibility of the vote, and the opposition has demanded a UN enquiry into police violence.
Conde's proposal to change the constitution has been hugely controversial, spurring mass demonstrations in which at last 32 people have been killed, according to an AFP tally.
The government argues that the constitution needs to be updated to usher in badly-needed social changes, especially for women.
Reforms would include banning female genital mutilation and under-age marriage and giving spouses equal rights in a divorce.
However, critics fear the reforms will also reset the presidential term counter to zero, potentially enabling Conde to govern for another 12 years.
Conde has not denied that he might use the proposed changes to seek another term.
After the referendum results were announced on Saturday, protesters in the northern city of Labe took to the streets, torching cars and setting up barricades, witnesses told AFP.
A former opposition figure jailed under previous hardline regimes, Conde made history in 2010 as the first democratically-elected president in a country with a history of military coups and turmoil.
Voters returned him to office in 2015 for his second and final five-year term under the current constitution, but critics say he has become increasingly authoritarian.