Washington (CNN) Dairy-product company Land O'Lakes and pet-food giant Purina on Tuesday announced they would no longer financially support Iowa Rep. Steve King after their political donations to the Republican spurred online criticism.

Land O'Lakes Political Action Committee donated $2,500 in late June to King's re-election campaign.

"We take our civic responsibility seriously, want our contributions to be a positive forces for good and also seek to ensure that recipients of our contributions uphold our company's values," the PAC said in a statement . "On that basis, we have determined that our PAC will no longer support Rep. Steve King moving forward."

It was joined Tuesday afternoon by Purina, which gave $500 to King in September. King's "recent statements are in conflict with our values and we are no longer contributing to his campaign," the company said on Twitter.

Our PAC contributions are typically made to elected officials from both parties who represent the local communities where we have operations and associates. Representative King's recent statements are in conflict with our values and we are no longer contributing to his campaign.

The sudden corporate retreat from King, an immigration firebrand who has a long history of controversial remarks, comes as he faces one of the most difficult campaigns of his 16-year congressional career. Democrat J.D. Scholten, a former professional baseball player, has snagged big sums and big endorsements in his quest to oust King.

In a further sign of trouble for King, a key player in his own party joined the rebukes Tuesday.

Rep. Steve Stivers, the head of the GOP's House campaign arm, condemned King's comments and actions as "completely inappropriate"

In a statement Tuesday afternoon on Twitter, King did not specifically address the actions of Stivers or the companies withdrawing support but decried the "attacks" against him as "orchestrated by nasty, desperate and dishonest fake news."

The goal, King said, is "to flip the House to Democrats and impeach" President Donald Trump.

The corporate moves came after prominent figures, including former Vermont governor Howard Dean, TV host Soledad O'Brien and Judd Legum, who writes a political newletter Popular Information, had denounced the donations in recent days on Twitter

Another large firm, computer chip-maker Intel, recently said it would withdraw support from King, after donating $2,000 to the eight-term congressman.

Land O'Lakes has handed out a little more than $363,000 this election cycle to candidates -- 64% of which went to Republicans, according to the non-partisan Center for Responsive Politics.