Alliance Assembly member Mr David Ford today become the first member of the cross-community party to formally declare his candidacy for the leadership.
The South Antrim MLA said today he would be seeking to unite the party and campaigning on the basis that a new form of apartheid should not be allowed to develop under the Belfast Agreement.
The former Stormont chief whip said: "I am putting myself forward as a candidate on the basis of my record of service to Alliance which includes almost 12 years of full-time work as general secretary of the party and as an MLA.
"I will seek to unite the party and look forward to the future," he said. "We now have to develop a role for our unique party in the face of an agreement that has instituted power-sharing but done little to break down sectarianism.
"That can only be done by developing an alternative vision, emphasising the need for a shared society and warning of the dangers of the Agreement developing a new form of apartheid," Mr Ford said.
He said he had not been afraid to speak out against the limitations of the Agreement in the three years since it was signed.
Three other possible candidates to succeed Mr Sean Neeson have yet to formally declare they are running.
They are deputy leader and North Down MLA Ms Eileen Bell, former deputy leader and Lagan Valley MLA Mr Seamus Close and Strangford MLA Mr Kieran McCarthy.
Mr Neeson's successor will be chosen by the party's governing council at a special meeting on October 6th.