A mainland watchdog group is crying foul over a “God bless the military” sign on the Marine base in Kaneohe, claiming the display violates the U.S. Constitution. 

Military Religious Freedom Foundation sent an email Thursday to Col. Sean Killeen, commanding officer of Marine Corps Base Hawaii, asking that the sign be moved to the chapel grounds or removed. 

The advocacy group alleges the sign is a “brazen violation” of the Establishment Clause of the Constitution, which forbids the government from promoting one religion over another. 

The group’s email said the sign “sends the clear message that your installation gives preference to those who hold religious beliefs over those who do not.” 

The sign, located on a road leading to the marina, reads in full: “God bless the military, their families, and the civilians who work with them.” 

MRFF is a nonproft with a mission of protecting the religious freedom of U.S. military members. 

MRFF’s founder, Mikey Weinstein, said by phone from New Mexico on Thursday that 23 Marines, from the ranks of the enlisted to officers, have complained about the sign to his organization over the past two weeks. 

He said the sign stands out “like a tarantula on a wedding cake” on the small base. 

He said the Marines — 21 of whom are Protestant — have not used the chain of command to lodge a complaint because they fear reprisal. 

Capt. Tim Irish, spokesman for Marine Corps Base Hawaii, said the commanding officer received an emailed complaint about the sign and ordered his staff to research the sign’s origin and its compliance with existing regulations. 

He said the Base Inspector’s Office is also investigating whether there have been complaints in the past about the sign, which may have been there for years. 

“MCBH will exercise due diligence to ensure compliance with existing regulations and law, including theEstablishment Clause of the U.S. Constitution,” he said in an email.