A top GOP donor has launched an advocacy group to push Congress to pass gun control laws.

Al Hoffman Jr., a Florida-based real estate developer and former Bush administration official, started Americans for Gun Safety Now, according to Time magazine.

Hoffman officially launched the group on Saturday, coinciding with the March for Our Lives, where hundreds of thousands of young people worldwide are marching to call for gun control and school safety in response to the Florida high school shooting in February.

After the Florida shooting, Hoffman, a former ambassador to Portugal, told GOP leaders that he would not make any more contributions unless they passed a ban on assault weapons.

"I will not write another check unless they all support a ban on assault weapons," Hoffman wrote in an email, according to The New York Times. "Enough is enough!"

ADVERTISEMENT

Americans for Gun Safety Now, which reportedly has 21 major supporters, including some GOP lawmakers and donors, has outlined a six-point plan for gun control legislation, including expanded background checks and eliminating bump stocks.

President Trump Donald John TrumpBubba Wallace to be driver of Michael Jordan, Denny Hamlin NASCAR team Graham: GOP will confirm Trump's Supreme Court nominee before the election Southwest Airlines, unions call for six-month extension of government aid MORE moved this week to ban bump stocks, the devices used in the Las Vegas mass shooting that modify semi-automatic weapons to fire more rapidly.

Hoffman told Time that he thinks GOP lawmakers are at risk of losing “big” in the midterm elections if they do not act on gun control.

He added that he plans to encourage other GOP donors to withhold donations unless the lawmakers endorse the plan.

“We’re in deep limbo with a number of congressmen and senators right now, but we’ve got to kick them in the butt and get it going on this. For our own sake,” he said. “I’m going to encourage anyone who is involved with giving money to any member of the Republican party not to give money to these candidates that will not endorse this plan.”