Opposition parties for Nigeria ogbonge election go make attempt to do wetin some don describe as di impossible - get court to overturn di outcome of di presidential election for Africa most populous nation.

Peter Obi and Atiku Abubakar, di second and third-placed candidates for di tightest presidential election since di end of military rule for 1999, dey go court to challenge di result wey see Bola Tinubu of di ruling party declared di winner with 37% of di vote.

While Mr Abubakar of di main opposition Peoples Democratic Party (PDP) call di result "a rape of democracy" afta e get 29% of di vote, di Labour Party Mr Obi, wey get 25%, tell im supporters say dem don "rob" dem of victory, and promise to "prove am to Nigerians".

But which evidence dem get and wetin be dia chances of overturning di result?

Wen di parties need to file?

All petitions challenging election for Nigeria must dey filed within 21 days of di announcement of di results or dem no go dey considered.

So Peter Obi and Atiku Abubakar go need to send dia petitions to di appeals court tribunal for di capital, Abuja, before 31 March.

While dis one dey encourage di trial to happun fast-fast, and fit dey straightforward wit local elections, e fit be ogbonge task to collect evidence from di more dan 176,000 polling units or more dan 8,000 area collation centres wia dem first receive results for di presidential poll.

How long e go take to reach a verdict?

A written result from di tribunal go dey expected 180 days afta dme file di suit, and as Messrs Obi and Abubakar dey expected to file separately, decisions go come at different times.

However, di decision of di tribunal no dey final and di parties fit decide to head to di Supreme Court for a conclusive verdict. Dat process dey take 60 days, so a final decision fit come within eight months.

Shey e go affect di inauguration?

No.

E dey highly unlikely say di tribunal go reach a decision before 29 May - wen Mr Tinubu dey due to be sworn in as president.

Even if di tribunal order a rerun or declare any of im opponents di winner of di election, such an outcome dey most likely to be challenged for di Supreme Court.

Wetin di law tok about transmission of results?

Wen journalists press am to disclose which evidence e get say e win di election, Mr Obi refuse to tok, while Mr Atiku say wuru-wuru dey di "processes and outcome" of di election.

But going by di speech of di PDP representative for di centre wia dem announce di results before both parties waka comot, e dey likely say their respective cases go base on di electronic transmission of results from di polling units.

Dem sign one act last year to guide di conduct of di 2023 elections and e say "voting and transmission of results go dey in accordance with di procedure determined by di [Independent National Electoral Commission (INEC)]."

Di act mandated Inec to publish guidelines for di elections clearly outlining di steps from recording di results for di polling unit to di last collation centre for di ward or constituency.

Inec come publish im own guidelines for di election wia e tok say officials go:

- Electronically transmit or transfer di result of di Polling Unit directly to di collation system
- Use di Bimodal Voter Accreditation System (Bvas) to upload a scanned copy of di EC8A (result sheet) to di Inec Result Viewing Portal (IReV)
- Di new electronic system, Bvas, bin dey intended to speed up di delivery of results and make am harder to interfere with votes, however many voters report say Inec staff bin either dey unable or unwilling to upload results to di website, e raise fears say e fit be a sign of a plot to rig di election.

Inec blame high traffic for dia inability to publish di results in real time, but almost a week afta dem cast di first ballot, dem never still publish 12% of di results.

Senior Nigerian lawyer Yemi Candide Johnson tell BBC say Inec guidelines no be law and say election can only be nullified for substantial non-compliance with di electoral law.

"If non-compliance no affect di result e no go nullify [di result]. If certain results for certain areas no dey compliant, a rerun dey possible only if e go mata," e tok.

Which oda evidence dey?

Since Mr Obi say e win di election, e fit demand say make dem demand declare am di winner. Several complaints of malpractice dey in places such as Rivers, Delta, Imo, Sokoto and Lagos, wia opposition parties accuse Inec staff of conniving with di ruling party and security officials to manipulate results for di ward collation centres.

Sabi pipo wey don dey compare results wey dem post on di Inec website with hard copies dem take for dia polling centres and dey claim say e no rhyme. Labour Party don create digital platform for im young supporters to document dat kain irregularities by posting results from dia polling units so dem fit compare am wit wetin dem announce for di ward collation centres.

Some of di results on di Inec website, dem post am for di wrong states, while dem cancel-cancel odas. Though some pipo don also confam di results from dia polling units match with those on di Inec website.

If Mr Obi suspect say di results don dey tampered wit to reduce im votes for certain areas and increase those of di winner, e go need to present original copies of di result sheets and di electronic machines dem use to accredit voters from di contested places to back up im claims.

Mr Obi also hint say deliberate policy dey of making am hard to vote and of manipulating di results, especially in some areas wey dem see as im strongholds. Although 87 million pipo bin dey eligible to vote for dis election, just 27% of dem cast dia ballots, di lowest since 1999.

Inec officials land hours afta polls don close for some southern states, or no show up at all for odas.

However, to win a case for court, di opposition parties go need to prove say e dey deliberate, and say e affect di outcome of di poll.

Wetin dem need to prove?

According to di electoral act, a petitioner need to prove say non-compliance with provisions of di law make a difference to di outcome of di election.

Instances of manipulation or say violence scata di election go need to don happun for a majority of di polling units or collation centres.

Di difference between Mr Tinubu and Mr Abubakar is close to two million votes, while Mr Obi dey behind wit 700,000 votes.

Though Nigeria previous elections dey most times get problems like violence, voter suppression or ballot-box snatching on election day, no presidential candidate don dey able to prove say such irregularities affect di outcome on a significant level.

For 2003 wen current President Muhammadu Buhari challenge di victory of Olusegun Obasanjo, one Supreme Court judge say di plaintiff need a minimum of 250,000 witnesses to establish a case of non-compliance for di conduct of a presidential election to win dia case.

While di law don since change to drop di need for dis kain roll-call of witnesses, e show di kain challenge di petitioners go face.

However, dis na di first national election wey dem conduct wit di electronic transfer of results and while di system get some problems on election day, dem don gradually dey upload di results from di polling units to di Inec website, so e suppose make am easier for di petitioners to access di evidence dem need.

Di opposition go fit win dia case?

Although no presidential result don ever dey overturned, e don happun with several oda elections for Nigeria.

And Mr Obi na one of di beneficiaries.

E get to wait three years before e enta into office for 2006 afta e successfully prove say e win di govnorship election of Anambra state for 2003.

E bin dey able to prove for di tribunal and di appeal court say e receive di most votes for di election and dem declare am di winner.