London, Apr 7: Democrat presidential hopeful Hillary Clinton's chief strategist Mark Penn resigned after embarrassing her by flying to Colombia on private business to lobby for a free trade deal that she opposes.

Hillary is on the presidential campaign trail in Oregon and is struggling to keep alive her election hopes alive.

The departure of her top official is a major blow to Hillary and could help fuel a sense of crisis in her candidacy, the Telegraph reported.

But several other senior advisers had long argued that Penn should be fired because his strategy of making her the "inevitable" candidate" had plainly failed.

Some blamed him for Hillary's current dire situation, in which her chances of defeating Senator Barak Obama diminish almost by the day.

There had been open dissent in recent weeks with other advisers publicly mocking Penn, who ran then President Bill Clinton's re-election campaign in 1996.

Hillary faced further embarrassment on Sunday after a story she told about the state of America's health care system was disclosed as inaccurate. (ANI)