Democrat frontrunners Sen. Bernie Sanders (I-VT) and Sen. Elizabeth Warren (D-MA) will appear on the same debate stage Tuesday night, but Democrats are not sure if viewers should expect fireworks between the two.

Earlier this year, rumors swirled that Sanders and Warren, who have described each other as long-time friends, had a “pact” to refrain from going out of their way to criticize one another during the course of their campaigns. While they have seemed to abide by it, Democrats are not sure what to expect ahead of Tuesday night’s debate. Some believe they will band together to promote their mutually-held far-left views.

Adam Green of the Progressive Change Campaign Committee told NBC News that he expects “some fireworks” but not between Sanders and Warren.

“Warren and Sanders will be a one-two punch … mutually reinforcing each other’s call for a bold, progressive, transformational presidency,” he told NBC.

As Breitbart News reported, the two top tier candidates are ideologically similar, especially on key progressive topics like climate change, “corporate greed,” free college, and Medicare for All.

During the last debate, Warren praised Sanders’ Medicare for All plan.

“I’m with Bernie on Medicare for All. And let me tell you why,” Warren told NBC moderator Lester Holt.

“There are a lot of politicians who say, ‘Oh, it’s just not possible. We just can’t do it’ — have a lot of political reasons for this,” she continued:

The question remains: Will Sanders and Warren team up in order to advance the ultra-left ideas they commonly support?

Warren reportedly said she was ready to “defend” all of her plans and noted her friendship with Sanders during a campaign stop in New Hampshire over the weekend. Even Sanders’ campaign manager Faiz Shakir signaled that Sanders does not plan to attack his progressive ally.

“There are other candidates on that stage, and also the next night, who believe in a middle ground approach, so I think like you’re going to have Elizabeth Warren and Bernie Sanders end up agreeing on a lot of fundamental policy issues,” Shakir said, according to NBC.

It is likely that the two candidates will attempt to distinguish themselves, and their far-left ideas, from the likes of “moderates” like Joe Biden (D), who will not join them on the stage during the second round.

The current Real Clear Politics average shows Sanders and Warren in a tight race for second place, with Sanders averaging 15.3 percent and Warren garnering 14.7 percent.