One of Hillary Clinton's closest advisors and strategists Mark Penn has stepped down from the campaign as a result of his contacts with the Colombian government over the free trade agreement - an agreement that his candidate opposes but which he has lobbied for on behalf of the Colombians:

Penn had been a polarizing figure within the Clinton campaign for months because of his personality as well as his strategic vision, but his departure came as a result of another continuing controversy -- the conflicts of interest that resulted from his representing major clients as president of Burson-Marsteller, the giant public relations firm, while working for Clinton.

Last week, the Wall Street Journal reported that Penn had met with Colombia's ambassador to the United States to discuss promotion of a free-trade agreement, one that Clinton opposes. Penn apologized Friday for an "error in judgment," and the Colombian government responded a day later by firing Burson-Marsteller.

Clinton and her husband, Bill Clinton, were furious with Penn for going to the meeting, campaign officials said. Trade has been a divisive issue in the Democratic race and a particularly significant one in Pennsylvania, the next state on the primary calendar.

The senator from New York has pledged to take a "timeout" from free-trade agreements until their impact on the United States becomes clearer.