The race to succeed Martin McGuinness as MP for the Mid Ulster constituency has been confirmed as a four-way fight.
There were no late entries to the ballot for the by-election before nominations closed late on Thursday.
The four contenders are Sinn Fein Assembly Member Francie Molloy, independent Nigel Lutton, the Social Democratic and Labour Party's Patsy McGlone and Eric Bullick of the cross-community Alliance Party.
Mr Molloy, the principal deputy speaker at the Stormont Assembly, will attempt to retain the solid Sinn Fein seat, first won by his party colleague Mr McGuinness in 1997. He is defending a sizeable majority of more than 15,300.
Stormont Deputy First Minister Mr McGuinness said he was resigning his Westminster seat as part of his party's policy to end double-jobbing in politics.
The main unionist parties are not fielding candidates and have instead thrown their support behind so-called unionist-unity candidate Mr Lutton, who is set to be Mr Molloy's main rival.
Mr Lutton's father, Frederick, was a former RUC reservist who was shot dead by the IRA in 1979. That murder could be a major issue in the campaign as, in 2007, Upper Bann Democratic Unionist MP David Simpson used parliamentary privilege to allege that Mr Molloy had been a live suspect in the killing.
The long-standing Sinn Fein politician has strongly denied the allegation, while Mr Lutton has insisted that his decision to stand was not because Mr Molloy was running.
The emergence of the unity candidate has had major ramifications for the Ulster Unionist Party. In the wake of the UUP's decision to back Mr Lutton, two of its high-profile Assembly Members - Basil McCrea and John McCallister - resigned in protest.
The by-election will take place on March 7.