The Green Party’s Jill Stein has offered Vermont Senator Bernie Sanders top billing on her party’s ticket, should he choose to leave the Democrats, the party that has, by all appearances, resisted him throughout his wildly popular campaign.

While Sanders is still technically a Democratic Party presidential candidate, he has yet to endorse frontrunner Hillary Clinton, though he has ceased campaigning for delegates and appears to be winding down his efforts. Stein, however, is urging him to continue his political movement within her party.

“I’ve invited Bernie to sit down explore collaboration – everything is on the table,” Stein told the Guardian. “If he saw that you can’t have a revolutionary campaign in a counter-revolutionary party, he’d be welcomed to the Green Party. He could lead the ticket and build a political movement.”

She further stated that Sanders would be disappointed “if he continues to declare his full faith in the Democratic Party.”

Recent polls have shown that only 55% of Sanders supporters will vote for Clinton if she is the nominee. Out of the 45% remaining, 22% of Sanders supporters plan to vote for Donald Trump if Clinton is the nominee, 18% have vowed to vote for Libertarian Candidate Gary Johnson — another 5% said they will either vote for Stein or stay home in November.

“That political movement is going to go on — it isn’t going to bury itself in the graveyard alongside Hillary Clinton,” Stein stated.

According to national polls, Stein is currently polling between 4 and 6%, but a boost from Sanders supporters may get the Green Party the attention needed to enter the presidential debates.

“I’m not holding my breath, but I’m not ruling it out that we can bring out 43 million young people into this election,” she said. “It’s been a wild election; every rule in the playbook has been tossed out. Unfortunately, that has mainly been used to lift up hateful demagogues like Donald Trump, but it can also be done in a way that actually answers people’s needs.”