Meyers said challengers will show that thousands of people who signed the petition were not registered to vote in Oklahoma and therefore ineligible to sign the document.
Many of the petitions were circulated by people who were ineligible because they were from out of state and not Oklahoma residents or voters, Meyers said.
Some of those circulators registered in Oklahoma motels but gave their address as another state, he said.
Other circulators used addresses that turned out to be a hotel, he said.
Some also listed motels as their address, but the motels had no record they ever stayed there, he said.
Kieran D. Maye Jr., one of the attorneys for the promoters of the proposal, said the challengers won't be able to knock out enough signatures.
He told Albert the Supreme Court has said that convincing evidence is required to disqualify a signature.