He is expected to set out a vision to unite the party with policies aimed at appealing to a new generation of voters that he believes are "desperate" for a left-wing Labour government.
He appeared in a list of possible candidates to replace outgoing leader Ed Miliband following Labour's second successive general election defeat past year.
"A lot of people are angry that they were quite clearly misled by the Brexit campaign".
Ms Eagle however indicated that she may be willing to run in a three-way battle against both Mr Smith and Mr Corbyn, telling a central London event: "I will leave Owen to do this own thing, I'll do my own thing". "That's what I am determine to provide, this leadership that we need", Owen Smith said on Wednesday.
"Whilst Jeremy is a good man with great Labour values who has done a lot for this party and I think changed the debate in this country about our economy - he's been right about lots of things - but he is not a leader who can lead us into an election and win for Labour", Mr Smith told the BBC on Wednesday.
However, with the leadership contest now beginning, junior whips - some of whom have already made clear to their Constituency Labour Parties (CLPs) that they voted against Corbyn in the no confidence ballot - have chose to support either Angela Eagle or Owen Smith.
He said: "I think she would make an excellent leader of the party and if she were the leader of the party, I would work very happily alongside her".
PoliticsHome understands that many MPs who had previously given their backing to Ms Eagle are now supporting Mr Smith's leadership bid.
She said there should be no legal challenge to the NEC's decision but warned that Labour risks electoral wipeout in the north at the hands of Ukip, similar to that it has suffered in Scotland if Mr Corbyn remains leader.
"I refused to have any part in discussions, which have been destructive, from a small group of people on the right who, just like those on the left, it seems to me, are now prepared to let Labour split".
"I will stand in this election and I will do the decent thing and fight Jeremy Corbyn on the issues, just as he will do with me, and at the end of that I will stand behind whoever the leader is".
"And finally, an inability that Jeremy has to have his parliamentary party convince him of anything - no reaching out, a pushing away".