Standing alongside Matthews at the launch of the 'Fresh Start' ticket in Brisbane on Tuesday morning, Kelly implored Lions members to reinstate the four-time premiership coach to the club's hierarchy.
Matthews said he would only be involved on the Lions board if his ticket, which includes current board members Mick Power and Paul Williams, was successful.
If current chairman Angus Johnson wins on November 13, Matthews walks.
"If they're (Fresh Start) not successful, I'm not on the board, it's a simple principle," Matthews said.
But in Kelly he has a strong ally.
After 12 years as a Lions director himself, Kelly resigned from his post as chairman in 2010, leaving Johnson to take over.
With a passionate address, he has now urged Lions members to support Matthews and oust Johnson.
"This is a once in a lifetime opportunity for the Lions members to get a powerful and harmonious group together," Kelly said.
"It is a once in a lifetime opportunity to have Leigh Matthews as their football director.
"After November 13, there will be no other opportunity - I encourage the members to think about that.
"It is not about who is acting in the best interests of the club, the question now is what is best for the club."
At Tuesday's press conference, Matthews, Power and Williams were flanked by Ross Thornton and Dr Allan Smith, who would also join the board if the Fresh Start ticket is successful.
Since the rival ticket was formed in late August, the Lions' boardroom brawl has been played out very publicly and AFL mediation has been unable to prevent an EGM.
In a strong show of solidarity, the Fresh Start group also had a number of high-profile Lions personalities and former stakeholders lending their support.
"There was a drifting away of people who had been really big supporters," Matthews said.
"There was all these people keen for a change because they felt like there was a disengagement with members."
Power, a property developer and one of the richest men in Queensland, said the club was financially in a precarious position, but would survive with the AFL's help.
"The Lions will come back, we just need the right people on the board driving it and a big part of that will be Leigh in the football department," he said.
"This is the only ticket that can deliver him."
Meanwhile, the Lions have taken steps to distance themselves from Dr Henry Pinskier, who has emailed members in an attempt to get their proxy votes for the EGM.
In a statement released on Tuesday, the club said it had no official relationship with Pinskier's 'Restore the Lions' Pride' group.
"Members will be advised in official notices of how they can lodge their vote at next month’s EGM," the statement said.
The Lions are also investigating privacy concerns, after Pinskier's group obtained the club's members' email list.
The Pinskier group has since sent emails to selected members with details of the EGM venue and time, along with other information that should have been only in the hands of the Lions' board and selected other people.
"The club takes this matter very seriously and is continuing to look into how this data may have been acquired," the statement said.
Twitter: @AFL_mikewhiting
