A source with knowledge of Hillary Clinton's plans has confirmed that she will officially announce her 2016 presidential bid on Saturday or Sunday. This will be imminently followed by campaign travel.

A spokesperson for Clinton's campaign team did not immediately respond to a request for comment from Business Insider.

Clinton has long been expected to enter the 2016 race. Polls show her well ahead of all her likely Democratic and Republican rivals.

Hillary Clinton AP She has been ramping up her presidential preparations including leasing office space for a headquarters in Brooklyn, New York, and hiring key staffers.

On Tuesday, CNN reported Clinton's official announcement was "likely only days away."

Two Democratic challengers to Clinton, former Virginia Senator Jim Webb and former Rhode Island Gov. Lincoln Chafee have also officially launched 2016 presidential exploratory committees.

Former Maryland Gov. Martin O'Malley is also considering entering the race.

On the Republican side, Sen. Ted Cruz (R-Texas) and Sen. Rand Paul (R-Kentucky) have both formally launched campaigns. Sen. Marco Rubio (R-Florida) has a "big announcement" scheduled for an event in Florida next Monday.

Sen. Marco Rubio (R-FL) Joe Raedle/Getty Images Clinton's plans to kick off her campaign this weekend could complicate Rubio's kickoff.

Both Cruz and Paul enjoyed substantial coverage after their announcements.

Cruz also saw his poll numbers improve following his official launch.

Coverage of Clinton's announcement and subsequent trip could diminish the attention give to Rubio's kickoff because of her status as a strong frontrunner.

In a message to Business Insider, an operative for one of the other 2016 campaigns teased Rubio about being "overshadowed."

"Poor Marco, overshadowed again," the operative wrote.