Welsh Assembly member Gareth Bennett is standing for the leadership of UKIP.
Gerard Batten has confirmed he is leaving the post after little more than a year in charge, triggering a contest.
UKIP lost all its European Parliament seats in last month's election, which saw victory for former UKIP leader Nigel Farage's Brexit Party.
Mr Bennett said he believes his "comprehensive manifesto" could "rebuild our party and put UKIP back on the political map".
The South Wales Central AM had led the UKIP group in the Welsh Assembly until the defection of David Rowlands to the Brexit Party.
This left UKIP with just two AMs - Mr Bennett and Neil Hamilton - meaning it no longer qualified as a group.
Announcing his leadership bid, Mr Bennett admitted UKIP had had "a tough time" in recent years.
"We need a fresh approach that can take UKIP forward and help our dedicated activists to get elected," he said.
Mr Bennett unveiled what he called "bold" policy ideas, including the introduction of a national identity card, and a referendum on a subject chosen by the public in every Parliamentary term.
He added: "Such a referendum, if the motion is passed, would be implemented by a specially appointed team of legislators and draughtsmen, and would bypass the MPs."