Ted Cruz is 'Lucifer', says ex-speaker John Boehner

US presidential hopeful Ted Cruz has been called "Lucifer in the flesh" by the former Speaker of the House of Representatives, John Boehner.

Boehner, a fellow Republican, has also reportedly said he will not vote for Cruz if he becomes the nominee.

Their rift dates back to when Cruz led a group of hard-core conservatives to force a government shutdown in 2013, against his party's leadership.

Meanwhile, Boehner has described Donald Trump as a "texting buddy".

He also said they have played golf together for years and that he would vote for the billionaire if he were the Republican nominee, the Stanford Daily reported.

The billionaire is the front-runner on the race for the Republican nomination, ahead of Cruz.

The Texas senator is seen by many Republicans as the only option to prevent Trump from being the party's candidate. Others, however, dispute this, saying he is a divisive figure.

Boehner, who was the most powerful Republican in US politics for a time until he resigned last October, used strong language when he spoke about Cruz during a talk at Stanford University.

"I have Democrat friends and Republican friends. I get along with almost everyone, but I have never worked with a more miserable son of a bitch in my life," he said.

Cruz is credited with having a large role in the federal government shutdown in 2013, when Boehner was Speaker of the House.

The Texas senator is seen as having an aggressive posture and considers himself as an anti-establishment politician.

He reacted to Boehner's remarks on Twitter, saying: "Tell me again who will stand up to Washington? Trump, who's Boehner's "texting and golfing buddy," or Carly & me?”, he wrote, referring to Carly Fiorina, his pick for vice-president in an eventual candidacy."

When asked about the Democratic front-runner Hillary Clinton, Boehner reportedly impersonated her saying "Oh I'm a woman, vote for me," which received a negative reaction from the crowd.

He later said they had known each other for 25 years and that he finds the former secretary of state to be very accomplished and smart.