Bernie Sanders is positioned to officially throw his support behind Democratic rival Hillary Clinton in New Hampshire on Tuesday, CNN's John King reported on "Inside Politics" Sunday.
The move comes after the Democratic Platform Committee, meeting in Orlando, adopted some of the Vermont senator's key positions.
Climate change, health care and a minimum wage hike are among the issues that the Sanders campaign are calling victories.
However, some of Sanders' supporters are still critical of this upcoming endorsement, particularly over the party platform's language on trade.
Sanders has faced criticism from Democrats after continuing to delay his endorsement of the presumptive Democratic nominee.
Even after the primary season ended, Sanders stayed in the race and vowed to carry his fight to the convention. But Sanders has noted that he planned to work alongside Clinton to defeat Donald Trump in the general election.
A pending Sanders endorsement was among two outstanding issues for the Clinton campaign, along with questions over Clinton's email server use. That was side-stepped this week when the Department of Justice announced it would not press charges against Clinton, per the FBI's recommendation after the formal investigation concluded.
A Tuesday Sanders endorsement of Clinton would still cut timing close, though, with the Democratic convention in Philadelphia set to open in just over two weeks.