Rep. Robert Francis "Beto" O'Rourke (D., Texas) has been removed from a list of candidates who pledged to reject fossil fuel donations over $200 after it was revealed he took multiple contributions from oil and gas executives.

Oil Change USA, a nonprofit organization based in Washington, D.C., removed O'Rourke's name from a list of those who signed the pledge, according to Sludge. The pledge dictates a politician and their campaign "adopt a policy to not knowingly accept any contributions over $200 from the PACs, executives, or front groups of fossil fuel companies—companies whose primary business is the extraction, processing, distribution, or sale of oil, gas, or coal."

Sludge reported earlier this month that O'Rourke received $430,000 from individuals in the oil and gas industries. The report was later updated to note that "the O’Rourke campaign had not returned 29 ‘large donations' of over $200 from oil and gas executives," according to the most recent campaign finance report.

David Turnbull, Oil Change USA's strategic communications director, suggested O'Rourke thought the pledge only prohibited oil and gas PAC donations; however, the pledge referred to "PACs, executives, or front groups of fossil fuel companies."

"While we are pleased he hasn’t taken fossil fuel PAC money, he needs to go further in order to be in compliance with the full No Fossil Fuel Money Pledge," Turnbull said. "We hope to speak with members of Beto’s organization to encourage Beto to sign on to the full No Fossil Fuel Money Pledge, including rejecting major contributions from top executives of fossil fuel companies."

Oil Change USA describes itself as "dedicated to supporting real climate leadership, exposing the true costs of fossil fuels, and building a just, equitable, and renewable energy future in the United States."

O'Rourke is considered a potential Democratic presidential candidate for the 2020 election. A recent poll of likely Iowa caucus voters, conduced Dec. 10-13, found O'Rourke in third place behind former Vice President Joe Biden and Sen. Bernie Sanders (I., Vt.), but ahead of Sens. Elizabeth Warren (D., Mass.) and Kamala Harris (D., Calif.).