(CNN) The Veterans of Foreign Wars blasted Donald Trump Monday and a group of Gold Star families of fallen service members demanded he apologize for comments about the parents of a slain Muslim U.S. solider.
"Election year or not, the VFW will not tolerate anyone berating a Gold Star family member for exercising his or her right of speech or expression," said Brian Duffy, who was elected July 27 to lead the nation's oldest and largest major war veterans organization.
"There are certain sacrosanct subjects that no amount of wordsmithing can repair once crossed," added Duffy, the national commander of the near 1.7 million-member Veterans of Foreign Wars of the United States and its Auxiliary.
"Giving one's life to nation is the greatest sacrifice, followed closely by all Gold Star families, who have a right to make their voices heard."
The VFW statement came just hours after a group of Gold Star families wrote to Trump.
"Your recent comments regarding the Khan family were repugnant and personally offensive to us," wrote the group of 11 "Gold Star" families, who are those who have lost a family member in war. "We feel we must speak out and demand you apologize to the Khans, to all Gold Star families, and to all Americans for your offensive, and frankly anti-American comments."
The letter, published Monday on VoteVets.org, comes amid a chorus of criticism in response to Trump's burgeoning feud with the Khan family, which began after Khizr Khan, the father of slain Army Cpt. Humayun Khan, delivered a forceful condemnation of Trump in a speech at the Democratic National Convention. Trump responded by criticizing his wife, Ghazala Khan, for her silence during his speech and suggesting she wasn't allowed to speak.
"Ours is a sacrifice you will never know. Ours is a sacrifice we would never want you to know," the families wrote in the letter.
The group hit Trump for questioning why Khan's wife didn't speak at the convention, writing: "When you question a mother's pain, by implying that her religion, not her grief, kept her from addressing an arena of people, you are attacking us. When you say your job building buildings is akin to our sacrifice, you are attacking our sacrifice."
And the group rejected the idea that Trump was being unfairly criticized for his remarks out of "political correctness."
"You are not just attacking us, you are cheapening the sacrifice made by those we lost. You are minimizing the risk our service members make for all of us. This goes beyond politics. It is about a sense of decency. That kind decency you mock as 'political correctness.'"
Demanding an apology, they finish the letter by saying, "We hope you will hear us."
The Trump campaign did not immediately respond to a request for comment.