Mark Penn has resigned his position as chief strategist in Hillary Clinton's campaign, campaign manager Maggie Williams announced Sunday. According to Williams, Penn and his firm, Penn, Schoen and Berland Associates, Inc., will still be providing the campaign with polling and advice.

Penn has been a subject of controversy at various points throughout the race -- with plenty of criticism coming from inside the Clinton campaign, as well as from outside -- but he apparently could not survive his latest brush with it. On Friday, the Wall Street Journal reported on a meeting Penn had with the Colombian ambassador to the U.S. to discuss a bilateral trade deal Clinton opposes. Penn was reportedly there in his role as chief executive Burson-Marsteller Worldwide, a communications and lobbying firm.

According to ABC News' Political Radar blog, Penn resigned "under pressure from an angry Sen. Clinton, who believed that Penn had recused himself from any clients who might pose a conflict for her campaign." Two labor groups -- Change to Win and Unite Here, both of which have endorsed Obama -- had called for Penn's firing.

On Saturday, Colombia fired Penn's firm. In a statement announcing the move, the Colombian government said:

Mr. Mark Penn, President and CEO of Burson Marsteller, reponded to claims by Union representatives who questioned his relationship with the Colombian Government by declaring that it was an "error in judgment" to meet with his client the Colombian Ambassador on March 31. The Colombian government considers this a lack of respect to Colombians, and finds this response unacceptable.

Taking over the role Penn is leaving behind are Geoff Garin -- the campaign hired him as a pollster in March, which prompted observers to wonder if this meant Penn was losing influence within the campaign -- and Howard Wolfson, the campaign's communications director.