Washington (CNN) As President Donald Trump continues to publicly criticize Jeff Sessions, one of the attorney general's former colleagues is promising that if Sessions is fired, there will be "holy hell to pay."

"I'm 100% behind Jeff Sessions," Sen. Lindsey Graham, a South Carolina Republican, told CNN's Manu Raju Thursday morning on Capitol Hill. "If Jeff Sessions is fired, there will be holy hell to pay."

The Republican lawmaker also slammed Trump for what he views as an effort to "marginalize and humiliate" Sessions, adding that his Senate colleagues are also displeased with the recent barrage of attacks.

"This effort to basically marginalize and humiliate the attorney general is not going over well in the Senate," Graham told CNN. "If you believe Jeff Sessions should be fired, use the power you have and accept the consequences."

"I hope it stops," he added.

Despite Trump's Twitter attacks, Sessions has no plans to resign , sources have told CNN. Instead, Sessions is moving ahead with his duties as attorney general, including routine meetings with administration officials at the White House on Wednesday.

Graham then announced that he plans on introducing legislation next week to ensure that a special counsel cannot be fired if they are investigating the President, unless there is judicial review of the firing.

"I'm going to try to come up with statutory language that would say, in the case of Bob Mueller and future special counsels, that if the attorney general fires that person who's been empaneled to investigate the President or their team, then judges will have to look and see if whether or not the reasons stated meet the statutory definitions," Graham told CNN.

The South Carolina senator noted that this legislation is intended "not just for Trump, but for any future president," adding that "we need a check and balance here."

So why aren't the Committees and investigators, and of course our beleaguered A.G., looking into Crooked Hillarys crimes & Russia relations? — Donald J. Trump (@realDonaldTrump) July 24, 2017

Trump has lambasted Sessions on Twitter over the past week, calling the attorney general "beleaguered" and slamming him for a "weak position" on former 2016 presidential nominee Hillary Clinton.

"Attorney General Jeff Sessions has taken a VERY weak position on Hillary Clinton crimes (where are emails & DNC server) & Intel leakers!" the President tweeted Tuesday.

Trump also questioned why the attorney general and special counsel Robert Mueller were not looking into Clinton's deleted emails.

"So many people are asking why isn't the A.G. or Special (Counsel) looking at the many Hillary Clinton or Comey crimes. 33,000 e-mails deleted?" Trump tweeted over the weekend.

When asked whether he believes Donald Trump Jr. intentionally colluded with the Russians, Graham remains skeptical. Trump Jr., as well as then-Trump campaign chairman Paul Manafort and Trump son-in-law Jared Kushner attended a June 2016 meeting with a Russian lawyer who reportedly offered "compromising" information about Hillary Clinton.

"I think Don Jr. thought the meeting was okay. I'm not saying he intentionally violated the law. I really believe he thought it was something that all campaigns should do," Graham said.

But he cautioned that further investigations were necessary to determine the extent of the Trump team's contact with Russians.

"The reason this won't end any time soon is because how can you say with 100% certainty, given all the players here, there was never any more contact?" Graham told CNN. "The likelihood that the Russians just quit after one meeting, once the Trump campaign expressed desire to be helped, is pretty hard to believe but that may be the facts."

Attendees of the meeting have repeatedly said the June 2016 gathering was the only time they met.

"As it ended, my acquaintance apologized for taking up our time," Trump Jr. said in a statement obtained by CNN on July 9. "That was the end of it and there was no further contact or follow-up of any kind. My father knew nothing of the meeting or these events."