By Steve Holland
WASHINGTON (Reuters) - Republican presidential candidates, with the exception of Donald Trump, will test their messages in New Hampshire at a forum on Monday ahead of their first head-to-head debate in the 2016 campaign later this week.
Fourteen of the 17 candidates are to face off in Manchester, N.H., on Monday for the Voters Issues Forum at Saint Anselm College where each candidate will be asked questions by a moderator based on a random draw.
Most of the leaders in the Republican field are to participate, including Jeb Bush, Scott Walker and Marco Rubio, but not poll leader Trump, who declared he would not attend in outrage over a critical editorial published by the Union Leader, the Manchester newspaper that is one of the sponsors of the event.
The forum will allow candidates to see how they do against each other ahead of the first official Republican debate of the 2016 season on Thursday night in Cleveland.
The first debate has been controversial because under rules set up by the sponsor, Fox News, and backed by the Republican National Committee, only the top 10 candidates based on an average of recent national polls will be allowed on stage at the 9 p.m. event.
The remaining seven will face off earlier in the day at 5 p.m., a time when far fewer viewers will be tuning in.
Trump was in the lead in another poll. The NBC News/WSJ survey on Sunday showed him ahead with 19 percent, Walker trailing with 15 percent and Bush with 14 percent.
Ahead of the forum, Bush on Monday released a six-point plan to combat illegal immigration that includes offering 11 million undocumented workers "a rigorous path to earned legal status."
Bush proposed tightening border security through a more pro-active Border Patrol and greater surveillance, as well as a crackdown on both immigrants who overstay their visas and sanctuary cities.
"I am committed to addressing the problem of illegal immigration in a comprehensive fashion so we can respond to the legitimate concerns of the American people and build stronger support for legal immigration," Bush wrote in a blog on the medium.com website.
Others not planning to attend the forum are former Arkansas Governor Mike Huckabee and former Virginia Governor Jim Gilmore, who entered the race last week.
(Additional reporting by Alistair Bell; Editing by Cynthia Osterman)