The country's largest LGBT advocate for military service members said Tuesday it is organizing an opposition campaign to President Trump's pick for Army secretary.

OutServe-SLDN said Tennessee state Sen. Mark Green would be a "grenade in the tent" for recent civil rights advances in the military. The group was urging the public to sign a form letter to senators asking them to reject his nomination over past "hateful" statements.

"Mr. Green's anti-LGBT, anti-Muslim, anti-women record in the Tennessee legislature stands in stark contrast to the American values of justice, fairness and tolerance we all hold dear. He must not be confirmed," Matt Thorn, executive director for OutServe-SLDN, said in a statement.

It was the latest in a rising clamor on the political Left against Green, a conservative Christian lawmaker and former Army special operations flight surgeon. On Monday, Minority House Whip Steny Hoyer joined 31 fellow Democrats who are accusing Green with a history of homophobia and transphobia.

At least six other liberal advocacy groups for LGBT and Muslim rights have also in recent weeks called on the Senate to reject the nomination.

Green has denied he opposes any minority groups and said he would not bring politics into his role as the Army's highest civilian leader. He also implied liberal groups are intentionally misquoting and targeting him due to his devout Christian faith.

In posted videos, Green has voiced deep opposition to gay marriage, transgender bathroom rights, and the teaching of Islam in public schools.

"Mark Green is now denying, deflecting and distracting from his prior anti-LGBT actions, but his record speaks for itself," said Thorn, whose group claims 60,000 subscribers.

The letter campaign will show the Senate the broad opposition to Green's nomination, he said.