Senegal's former Prime Minister Macky Sall on Wednesday rallied the opposition to back him in a presidential run-off scheduled for March 18.

The former ally of President Abdoulaye Wade, Sall will take on the 85-year-old leader in a second round of voting after emerging as the runner-up in the first round last Sunday.

Sall vowed to revise the constitution to reduce the length of the presidential term from seven to five years, if he becomes president. He also made clear he would apply the shorter term to himself, as well as the two-term limit that is already present in the constitution.

Mr. Wade has admitted he fell short of the 50 percent of the votes needed in Sunday's poll to avoid a runoff. Provisional results show he has more than 30 percent of the vote, and Mr. Sall is trailing him by roughly seven points.

Final results are expected on Friday.

Cheikh Tidiane Gadio, one of eleven other presidential candidates, told VOA opposition leaders want to unite with civil society groups to oust Mr. Wade.

“Wednesday night, we will discuss to see if Macky Sall is ready to agree on what I call a citizen republican front, a national front, to get rid of Wade and his regime.”

Opposition leaders say President Wade's bid for a third term is unconstitutional, citing a reform he signed into law in 2001 that limits presidents to two terms. The presidentially-appointed Constitutional Court ruled last month that reform does not apply retroactively to Mr. Wade's first term.

The decision sparked riots, with protesters clashing with police. The pre-electoral violence killed at least six people, although demonstrations eased in the days leading up to the vote.

Elected in 2000 to great popular support, Mr. Wade has increasingly lost favor in the face of rising living costs, youth unemployment, and years of power cuts. Critics say the 85-year-old incumbent is too old for a third term and wants to transfer power to his unpopular son Karim.