House Democrats are accusing President Trump's pick for Army secretary of having a "history of homophobia and transphobia" that should disqualify him.

A group of 31 lawmakers is asking the Senate Armed Services Committee to reject the nomination of Tennessee state Sen. Mark Green. They sent a letter to the chairman, Sen. John McCain, R-Ariz., this week arguing that the former Army special operations flight surgeon cannot properly represent the service.

"LGBT soldiers are willing to make tremendous sacrifices to protect our rights and freedoms," wrote the lawmakers, who won't have any vote in Green's confirmation. "It would be deeply disrespectful to their service to appoint a secretary of the Army whose history of homophobia and transphobia makes it clear that he is not willing to do the same for them."

Green has also drawn fire from liberal civil rights advocacy groups and transgender reality TV star Caitlyn Jenner for comments he made over the past five years as a conservative Christian lawmaker in Nashville.

He responded on Facebook this week denying he disparaged any minority groups, blaming liberals for twisting his words and targeting him for being a Christian. Green also pledged to keep politics out of his service for the Army in an earlier written statement.

In various videos posted on the Internet, Green discusses his deep faith, opposition to gay marriage and transgender bathroom rights, and concerns that Tennessee students are being indoctrinated with Islam.

As secretary, Green would be the top civilian leader of the Army, which along with the rest of the military first allowed gay troops to serve openly in 2011 and transgender troops to serve openly last year. The last Army secretary, Eric Fanning, was the first openly gay man in that position.

"Mr. Green's past statements and actions have made it clear that he cannot be trusted to ensure that LGBT soldiers are able to serve their country without discrimination or harassment," the House Democrats wrote in the April 24 letter, first obtained by the Washington Blade.

The American Military Partner Association and the Human Rights Campaign have urged the Senate to reject Green over what they say is evidence he is radically anti-transgender and anti-gay.

Green said last year that most psychiatrists believe transgenderism is a disease and the Tennessee governor should oppose the nationwide legalization of gay marriage.

"We're not going to issue marriage licenses to gay people because our state voted differently," he told a Tea Party crowd. "OK, Supreme Court, you said it and I don't care. I'll back you up."

The Council on American-Islamic Relations, which bills itself as the country's largest Muslim civil rights group, has charged Green with Islamophobia for comments about public schools.

"When you start teaching the pillars of Islam and you start teaching how to pray as a Muslim, that is over the top and we will not tolerate that in this state," Green told a Tea Party audience last year.