Obama campaigners back female senator to challenge Hillary Clinton

In an open swipe at Hillary Clinton, more than 300 of President Barack Obama's 2008 and 2012 campaign personnel are urging a Massachusetts senator to step up as a challenger.

More than 300 operatives from President Obama’s 2008 and 2012 campaigns are urging Elizabeth Warren (inset) to challenge Hillary Clinton for the 2016 Democratic presidential nomination. Source: Associated Press

Mr Obama's campaign operatives say they aren't "ready for Hillary" in the 2016 elections and have openly backed Senator Elizabeth Warren for the Democratic Party nomination.

Their "Ready for Warren" site posted a letter on Friday signed by the ex-Obama staffers.

"Rising income inequality is the challenge of our times, and we want someone who will stand up for working families and take on the Wall Street banks and special interests that took down our economy," the group writes.

Ms Warren has said numerous times that she's not running but she also drew the attention of her nation this week by leading the charge against a $1.1 trillion spending bill because it stripped away trading restrictions on banks.