That assumption was made on the parties getting 41 percent, he said.
Morgan is asking National and Labour voters in a raft of electorates, including Auckland Central, Mt Albert and Manukau East, to "make their local vote count" by ticking TOP.
Morgan said those National and Labour voters can maximise the power of their vote and stop New Zealand First "holding their parties to ransom".
He did not expect National and Labour to endorse the campaign as, "their old establishment approach is what has kept Mr Peters around for the past 31 years of MMP".
At the press conference, Morgan could not say how much he was spending on the "Stop Peters" campaign.
He said the more important financial focus should be on New Zealand First, which he sais had a $55 billion deficit in his budget. The media were not holding Peters to account on that, Morgan said.
Peters was a "pork barrel politician", Morgan said.
"It's always about Winston, it's never about New Zealand as a group. He'll target one group and give them a hand out, that's buying people's vote."
Morgan listed Peters' history, beginning with his "abandonment" of his own party to form New Zealand First, and including his switch back to supporting Labour after the Clark government offered him "the baubles of office".
He said Peters politics were of the worst kind.
"He's xenophobic, racist and homophobic and he appeals to the worst side of our human nature," Morgan said. "I don't want him anywhere near parliament and any self-respecting New Zealander shouldn't either. That's what the Stop Peters campaign is about. Do you want progress or don't you."