Will Ferrell is producing a comedy about Ronald Reagan, but the late President's children aren't laughing.
Michael Reagan and Patti Davis, the son and daughter of President Reagan, are slamming the comedian's latest project, calling it an "outrage." The script, titled Reagan, reportedly centers on a White House intern who is tasked with convincing the POTUS that is he an actor playing the president in a movie when the latter falls into dementia during his second term. Ferrell is attached to star as the titular president.
WATCH: 11 of the Best 'Saturday Night Live' Political Sketches
"What an [outrage]," the younger Reagan tweeted on Wednesday. "Alzheimer’s is not a joke. It kills. You should be ashamed, all of you."
He followed with another tweet that read, "Alzheimer’s is not a comedy!"
READ: There's a Will Ferrell-Themed Bar in NYC and the Drink Names Are Insane
Meanwhile, Davis penned an open letter to Ferrell on her website.
"Perhaps you have managed to retain some ignorance about Alzheimer's and other versions of dementia. Perhaps if you knew more, you would not find the subject humorous," she wrote.
"Alzheimer's doesn't care if you are President of the United States or a dockworker. It steals what is most precious to a human being — memories, connections, the familiar landmarks of a lifetime that we all come to rely on to hold our place secure in this world and keep us linked to those we have come to know and love," she continued. "I watched as fear invaded my father’s eyes — this man who was never afraid of anything. I heard his voice tremble as he stood in the living room and said, 'I don’t know where I am.' I watched helplessly as he reached for memories, for words, that were suddenly out of reach and moving farther away. For ten long years he drifted — past the memories that marked his life, past all that was familiar…and mercifully, finally past the fear.
"There was laughter in those years, but there was never humor."
ET has reached out to Ferrell's rep for comment.
WATCH: Patti Davis Recalls How She and Her Mother Nancy Reagan Overcame Tumultuous Relationship
On the heels of a successful acting career, Reagan served as the commander in chief from 1981 to 1989. He died in his Bel-Air, California, home on June 5, 2004, of pneumonia, complicated by Alzheimer's Disease. He was 93.
Variety was first to report news of the casting, noting that the film does not yet have a director and will soon be shopped around to various Hollywood studios. The project first gained attention when it was featured as a top script on The Black List's catalogue, and recently received the live-read treatment from Lena Dunham and John Cho.
News of Ferrell's involvement comes less than two months after the death of Reagan's wife, Nancy Reagan. The former First Lady died from congestive heart failure on March 6 at her home in Bel-Air, California. She was 94.
WATCH: A Look Back at Ronald and Nancy Reagan's Love Story