Updated

Campaigning for Mali's watershed July 28 presidential election officially begins on Sunday, with the nation struggling to move on from war and return to desperately-needed constitutional order after an 18-month political crisis.

The ballot will be the first since a coup in March last year that ousted the democratically elected president, just months before he was due to step down at the end of his final term in office.

The transitional government lifted a nearly six-month state of emergency on Saturday, marking what officials hope will be a gradual return to normality ahead of the nationwide polls.

But critics of the process argue that it is being rushed and, far from restoring democracy, it threatens to plunge the deeply-divided west African nation further into chaos.

United Nations Secretary General Ban Ki-moon described the preparations last week as an "enormous undertaking".

"The situation in Mali is of great concern... It is vital that these elections be credible and peaceful, with an outcome accepted by all Malians," Ban told reporters in Geneva.

The coup toppled President Amadou Toumani Toure and created an opening that allowed groups allied to Al-Qaeda to seize northern Mali.

A UN peacekeeping mission integrating more than 6,000 west African soldiers into its ranks is charged with ensuring security during and after the elections, and will grow to 11,200 troops, plus 1,400 police, by the end of the year.

The deployment allows France to start withdrawing most of the 4,500 troops it sent to Mali in January to stop the Islamists from advancing towards the capital, Bamako, from their northern strongholds.

France plans to have just 1,000 troops on the ground before the end of 2013 and has been pushing for a quick election in the hopes of restoring order to the country, under the control of an interim government since the coup.

But Mali's election commission has expressed doubts it will be ready to hold the vote on July 28, with some 500,000 people still displaced after the conflict, and many observers have raised concerns over the security challenges in the conflict-scarred vast desert north.

Malian troops on Friday entered the last rebel stronghold, the key northern city of Kidal, which had been held by the Tuareg separatist National Movement for the Liberation of Azawad (MNLA) since the Islamists were driven out.

The lack of government control in the city was seen as a major obstacle to organising the election.

On Saturday scores of people hostile to the Malian army protested in front of their military camp in Kidal, where an African security source said "peace is fragile".

Tiebile Drame, architect of a peace deal enabling Malian troops to enter Kidal and secure the polls, told AFP on Thursday it was "very clear" that the elections would be "botched".

"The government is not ready, the minister of territorial administration is not ready, contrary to what he said, and the (election commission) is not ready," Drame said.

A European Union mission, made up of 90 observers, has begun work in Mali, and will report on whether the elections, which will go to a second round on August 11 if required, should be seen as credible a few weeks after the result is announced.

Headed by Belgian MEP Louis Michel, the observers are analysing each phase of the process, from the scheduling of the date and registration of candidates, through the campaign, election day itself and the count and announcement.

Tiebile Drame, architect of the peace deal enabling Malian troops to enter Kidal and a presidential candidate himself, told AFP on Thursday it was "very clear" that the elections would be "botched".

"The government is not ready, the minister of territorial administration is not ready, contrary to what he said, and the (election commission) is not ready," Drame said.

Mali's constitutional court released a list on Friday of the candidates, featuring four former prime ministers and an array of political heavyweights -- but just one woman.

Haider Aichata Cisse, a legislator for a constituency near the northern city of Gao, will go head-to-head with 25 men, including past premiers Ibrahim Boubacar Keita, Cheick Modibo Diarra, Modibo Sidibe and Soumana Sacko.