RFK Jr.’s Former Colleagues Call on Him to Drop Out of Presidential Race: 'Election Spoiler'

Staffers at The Natural Resources Defense Council, where Kennedy previously served as a senior attorney, will run a full-page ad Sunday

Staffers at one of Robert F. Kennedy Jr.'s former employers will urge him to "drop out" of the presidential race in a forthcoming newspaper ad, according to reports.

Outlets including CNN report that staffers at The Natural Resources Defense Council, where Kennedy served as a senior attorney for nearly three decades, will run a full-page advertisement in newspapers in six battleground states Sunday.

The ad, which was previewed by the network, reads: “We have spent our careers fighting to protect the planet and its people. As current and former leadership and board members of the NRDC Action Fund, as well as former colleagues of Robert F. Kennedy Jr., we have one message for him: Honor our planet, drop out."

The ad also calls Kennedy a "spoiler" candidate, claiming that his candidacy will ultimately benefit Republican contender Donald Trump.

“In nothing more than a vanity candidacy, RFK Jr. has chosen to play the role of election spoiler to the benefit of Donald Trump – the single worst environmental president our country has ever had,” the ad reads.

Related: Kennedy Family Members Snub RFK Jr. with Powerful Endorsement of Joe Biden: 'A Vote to Save Our Democracy'

RFK Jr. — the third of 11 children born to the late U.S. Attorney General and Senator Robert F. Kennedy and Ethel Kennedy and the nephew of the late President John F. Kennedy — announced his presidential candidacy last April.

In October, Kennedy announced his party switch from Democrat to Independent in a press conference given as he stood before signs reading "Kennedy 2024: Declare Your Independence."

Kennedy, who is known for spouting debunked misinformation about COVID-19 and vaccinations, has publicly butted heads with his family in the past. As he's ramped up his presidential bid, members of his famous family have coalesced behind Democrat Joe Biden.

Related: RFK Jr. Is Now Running for President as an Independent After Democratic Campaign Failed to Take Off

Several Kennedy family members joined Biden on the campaign trail on Thursday, offering a formal endorsement of their support.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Last year, four of Kennedy's siblings issued a statement saying his decision to run as a third party candidate was "dangerous to our country," adding:  "Bobby might share the same name as our father, but he does not share the same values, vision or judgment. Today's announcement is deeply saddening for us. We denounce his candidacy and believe it to be perilous for our country."

For more People news, make sure to sign up for our newsletter!

Read the original article on People.