Liberal activists are criticizing Republican Rep. Rodney Frelinghuysen over what they call the congressman’s “intimidation” of one of his constituents.

Frelinghuysen sent a campaign fundraising letter to a board member of Lakeland Bank in his district in which he says, “But let’s be clear that there are organized forces — both national and local — who are already hard at work to put a stop to an agenda of limited government, economic growth, stronger national security.”

In a handwritten footnote at the bottom of the letter, Frelinghuysen wrote, “P.S. One of the ringleaders works in your bank,” WNYC reported.

Saily Avelenda, who worked as vice president and assistant general counsel for the bank, said she resigned partially because of Frelinghuysen’s letter.

“I thought my Congressman put them in a situation, and put me in a really bad situation as the constituent, and used his name, used his position and used his stationery to try to punish me,” said Avelenda, an activist with the liberal group NJ 11th for Change.

NJ 11th for Change also criticized the congressman’s letter, saying in a statement, “We are outraged and alarmed by Representative Frelinghuysen’s intimidating action against an ordinary constituent, as reported this morning by NPR,” the group said in a statement. WNYC is an NPR affiliate.

Frelinghuysen’s office directed questions to his campaign, which issued a written statement saying, “The Congressman wrote a brief and innocuous note at the bottom of a personal letter in regard to information that had been reported in the media. He was in no way involved in any of the bank’s business and is unaware of any of the particulars about this employee’s status with the bank.”

But Democratic challenger Mikie Sherrill blasted the New Jersey Republican.

“Frelinghuysen has gone from simply refusing to meet with his constituents and telling them to ‘back off,’ to threatening constituents who are exercising their freedom of speech,” he said in a statement.