A referendum taking place on Sunday will determine whether President Sassou Nguesso can run for the third time ahead of next year’s election.
The 71 year old president, ruled Congo for 31 of the last 36 years and was recently forbidden to run for presidency again as a result of his age as well as due to constitutional term limits.
Under the current rules, the maximum age of presidential candidates is 70 and the maximum number of allowable times for being elected as president is two.
The former Marxist soldier was president from 1979 to 1992 in a one party state system. He then joined the opposition in 1992 after losing multi-party elections but returned to power at the end of the bloody civil war in 1997.
He was elected president in 2002, then again in 2009, when he won 79 percent of the votes but half of the opposition boycotted the most recent election.
It is not the first time Sassou has called Congo for a referendum. In the past he has called for "national dialogue" which resulted in removing the age limit for presidential candidates and increasing the term limits a candidate can stand for election.
Sasso's attempts have been described as a ''constitutional coup'' by Congolese opposition.
This month deadly demonstrations had taken place in capital city Brazzaville, there have also been demonstrations in other cities in Congo protesting against Congolese leader’s bid to extend the allowable number of ruling to three times.
Also on Friday, Nguesso’s presidential guards surrounded opposition leader’s resident, detaining him alongside three other opposition leaders opposed to a referendum.
Guy Brice Parfait Kolelas, the opposition leader and a former minister who was against the constitutional change in August, said that around 50 soldiers arrived on Thursday morning at his resident in military jeeps and began patrolling the compound.
He said "The only explanation is that I told the president he is not allowed to change the constitution," Kolelas told Reuters by telephone from his house. "He is trying to control us, to neutralise us."
In the Democratic Republic of Congo, opposition parties have blamed President Joseph Kabila, who has been in power for 14 years, for extending his time in office by using methods of violence and manipulation amid a busy electoral calendar.
In Burundi, President Pierre Nkurunziza faced deadly protests for months and a failed coup in April when he decided to run for a third term after a controversial court ruling that the first of his two terms did not count because he was not directly elected.
Also at the beginning of this month, the Supreme Court of Rwanda ruled that President Paul Kagame could run for a third term, and rejected the main opposition party's attempts to block changes in the constitution.