Alliance deputy Naomi Long is set to go unchallenged in her bid for the party leadership.
Declaring her intention to run for the post being vacated by retiring David Ford, the east Belfast representative vowed to "refresh, renew and re-energise the party".
Of Alliance's current party membership, only its eight elected MLAs are eligible to stand for the leadership.
With Mr Ford stepping down and all of the other six MLAs having signed Mrs Long's nomination papers, the former MP is set to be the only candidate on the ballot when members vote at a special Alliance council meeting at the end of the month.
A new leader is required to get over 50% of the available votes.
The period for submitting nominations formally closes at 5pm on Wednesday.
"Since David made the decision to step down as Leader after 15 very successful years at the helm, I have been heartened and encouraged by the support I have received from colleagues, the wider membership and many others across Northern Ireland to put my name forward as a leadership candidate," said Mrs Long.
"David has left a legacy of a growing, diverse and progressive membership, reflected in the broad-based support which I have received for my nomination, including members and elected representatives from right across Northern Ireland.
"If elected, I will not only be the first woman to lead the party, but it will also mark a generational change, as I will also be the first leader younger than Alliance itself.
"As such, I am conscious that, while the core values of the Alliance Party are still as relevant as ever, we need to be willing to renew our message, refresh our vision and re-energise not just our current members but a public growing increasingly weary of what often passes for politics here.
"I believe Alliance is ready to step up to that challenge. With the support of Party Council, I would be honoured to have the opportunity to guide that process forward as Leader."