The government in Gabon has made changes to the constitution which would allow President Omar Bongo to run for office as many times as he wishes.
Bongo has ruled Gabon for 36 years
The number of presidential election rounds has also been reduced from two to one.
The Gabonese leader has been in office for 36 years, making him Africa's second- longest serving leader after the President of Togo, General Gnassingbe Eyadema.
His current seven-year term is due to end in 2005, after which the next presidential elections will be held.
A senior opposition politician, Pierre Mamboundou, has criticised the amendments, saying that they had been made to ensure that President Bongo held onto power for life.
Appeal for help
Mr Mamboundou has called for intervention, saying that the rest of the world should not remain indifferent to what is happening in Gabon.
"The world has become a big village and the international community should not remain insensitive to what is happening in Gabon," Mr Mamboundou told his reporters in the capital, Libreville.
Since President Bongo came to power, the country's constitution has been amended 16 times.
Mr Mamboundou says the amendments were designed to ensure that President Bongo remained in power.
The opposition leader told his supporters in Libreville that during the next presidential elections the population will be mobilised to protect the final outcome.
He did not elaborate.