A collective of some 40 Senegalese civil society groups on Friday rejected the president's plan to leave open the date for the delayed presidential poll, saying it must be held before his term expires on April 2.

President Macky Sall had faced growing calls to set a date for the vote after his abrupt delay to the February 25 election triggered weeks of political crisis.

But in a televised interview late Thursday, he put off a decision on the date until after a dialogue with political and social actors due to begin Monday.

Sall said he hoped to reach an agreement by Tuesday evening.

One of the organisers of the Aar Sunu Election (Protect our Election) collective, Elimane Haby Kane, told AFP this was a "delaying tactic".

He added that the dialogue planned by the president "makes no sense".

The opposition has denounced Sall's last-minute move to delay the vote as a "constitutional coup", saying his party feared defeat at the ballot box.

The postponement plunged the traditionally stable West African country into turmoil and sparked unrest that has left four people dead.

Senegal's top constitutional body last week overturned the delay and called for the vote to be organised "as soon as possible".

On Thursday, Sall insisted his mandate would end as planned on April 2.

But he left open the question of when the vote would be held. When pressed, he added that he did not think it would be possible before April 2.

Sall, who has been in power since 2012, said he delayed the election partly over concerns about a return to unrest seen in 2021 and last year.

He has since insisted he wants dialogue to calm tensions and promote peace and reconciliation.

In an apparent move to pacify public opinion, Sall on Thursday said he would consider releasing imprisoned opposition figures Ousmane Sonko and Bassirou Diomaye Faye.

- 'Sweeten the pill' -

When asked about a poll date, Sall insisted that the forthcoming dialogue would decide "whether a consensus can be reached on the way forward".

If no agreement is reached, he said it would be up to Senegal's Constitutional Council to decide.

"Our position is (before) April 2, otherwise there will be a crisis," said Malick Diop, one of the organisers of Aar Sunu Election.

The collective mobilised several thousand people in the capital Dakar last weekend, and is sticking to rallies planned for the coming days.

A group of 16 presidential candidates was due to speak at around 11:00 am (local time and GMT) on Friday after holding consultations since Thursday evening, its coordinatory Cheikh Youm said.

One candidate, Thierno Alassane Sall -- no relation to the president -- took to social media to accuse Sall of fresh manoeuvres to stay in office.

He said he suspected the president would select divided participants for the dialogue and then use a lack of consensus to stay until the transfer of power, beyond April 2.

"To sweeten the pill, Macky Sall is offering us an amnesty", he added.

During Thursday's interview, Sall said he was considering the possibility of provisional releases, pardons or an amnesty law for opposition figures.