|Wade, 85, officially filed his presidential candidacy on Tuesday [EPA]
Human Rights group Amnesty International has urged Senegal to respect freedom of expression and assembly in the run-up to presidential elections scheduled for February.
The group's call on Wednesday comes after the country's authorities forbid demonstrations between January 26 to 30, with the ban starting one day before a key Constitutional Council decision on the validity of the candidates to stand for election.
The opposition is contesting the right of outgoing President Abdoulaye Wade, 85, to stand for a third term in the elections, which are scheduled to take place on 26 February.
Wade's efforts to run for a third term on a constitutional technicality has already led to violent clashes in one of Africa's most stable democracies.
"There is no apparent justification for this ban which undermines the right to demonstrate peacefully as enshrined in the Senegalese Constitution," said Salvatore Saguès, Amnesty's West Africa researcher.
"In this tense pre-election period where lawful political debate should be held freely, the authorities’ decision to prohibit public gatherings is all the more worrying."
Amnesty's statement comes as the the UN envoy for west Africa called for free and fair elections after meeting with Wade on Wednesday.
Said Djinnit, UN Secretary General Ban Ki-moon's representative, urged all parties to create conditions for a free, fair and peaceful election to reinforce democratic gains, stability and prosperity".
On Tuesday, Interior Minister Ousmane Ngom said on state radio that all protests between January 26 to 30 would be banned "to preserve peace and serenity".
"We don't want any pressure on the members of the Constitutional Council and those taking part in the decision," he said.
Tensions are running high in Senegal ahead of the decision by the five-judge body which is due on Friday, about a month before the poll on February 26.
Wade was first elected in 2000 for a two-term mandate, and re-elected in 2007.
But since the length of presidential terms was changed while he was in office, he argues that he can run again for office.
The president officially filed his candidacy on Tuesday.
Senegal's opposition on Wednesday called on people to defy the government ban on protests ahead of the Constitutional Council decision.
Main opposition leaders called on Senegalese people to join an "active resistance" against the government decree banning protests until Monday, a move they decried as a "violation of civil liberties".
"The minister's ban on protests is null and void and of no effect," the leaders said in a joint declaration by the June 23 Movement opposing Wade's candidature.
William Fitzgerald, US deputy assistant secretary of state for African affairs, said on Monday that Wade's bid to stay in office was "regrettable" and he should retire "to protect and support a good democratic transition in Senegal in calm and security".
Former colonial power France has refused to take a stand on his bid, saying it is for the Senegalese to decide.
Candidates have until Thursday to present their candidacies.
Among the main contenders are three of Wade's former prime ministers - Moustapha Niasse, Idrissa Seck and Macky Sall.
Also planning to run are internationally renowned singer Youssou Ndour and Ousmane Tanor Dieng, leader of the main opposition Socialist Party, which was in government for 40 years until Wade took over in 2000.