Mr Sessions' prepared remarks have been published on the committee's website.

In the document, he says: "the Department of Justice must never falter in its obligation to protect the civil rights of every American, particularly those who are most vulnerable."

The publication comes after concerns over alleged racist remarks and criticism by civil rights advocates. 

Image source, Reuters

Democratic Senator Dianne Feinstein says "there is so much fear in this country, particularly among African-Americans".

She quotes some people saying that they are troubled by Sen Sessions's stance on some key issues, including policing and discrimination.

But she stressed the independence of the office.

"As attorney general, his job will not be to advocate for his beliefs ... (but) to enforce the law." 

Ms Feinstein stressed that the attorney general does not take instructions from the president, and does not "wear two hats".

"He must ensure that the law and the constitution come first and foremost - period," she said.

Image source, Reuters

Just before the hearing started, some protesters on Capitol Hill in Washington made their opposition to Sen Sessions's appointment clear.

Sen Grassley has finished his speech, describing the nominee as a "man of honour and integrity... who knows well the Department of Justice".

He is now followed by Democratic Sen Dianne Feinstein, who will address the chamber.

A reporter for the New York Daily News managed to capture the earlier KKK-themed protest which briefly interrupted proceedings before the hearing began.

David Duke, former leader of the white supremacist KKK group, praised Mr Trump's choice of Jeff Sessions for attorney general in November.  

"We won't be voting for or against the president's policies... we'll be voting for a colleague with a first-rate mind... and eminently qualified to lead the Department of Justice," Sen Grassley said in his opening remarks.

He then listed some accomplishments of Mr Sessions, particularly stressing his experience as a public prosecutor.

Sen Grassley, a Republican, describes Sen Sessions as a "leader" who has served the people of Alabama with dignity.

If confirmed, he will be America's 84th attorney general, replacing Loretta Lynch.

The hearing has begun with a laying out of "ground rules" by the chair of the committee, Senator Chuck Grassley.

He said he is willing to stay until everyone has asked all their questions, in a series of rounds of questioning.

"We're here today to review the quality of character," of their colleague, he said.

So, just as the confirmation hearing is about to begin, several protesters are heard shouting anti-Sessions slogans. 

They are quickly restrained by security officials.

Image source, Reuters

The attorney general is both the head of the Department of Justice, and chief law enforcement officer of the federal government.

When the United States of America takes legal action against a person or company, it’s the attorney general’s office that represents the nation.

She or he also advises the president and other senior officials on legal issues.

The role is a cabinet-level position, and was created under President George Washington in 1789.

The holder is seventh in the line of succession for the presidency - in the unlikely event that the president, vice president, and four others die before elections are held.

Image source, Getty Images

Civil rights advocates have criticised Senator Sessions over his hardline views on gay rights, marijuana legalisation, immigration and criminal justice reform.

The National Association for the Advancement of Colored People (NAACP) has called Mr Sessions a "threat to desegregation and the Voting Rights Act".

So why is he so controversial?

• He was denied a federal judgeship in 1989 after the Senate Judiciary Committee heard testimony that he made racially offensive remarks
• He was accused of calling a black assistant US attorney "boy" and telling him to be careful about how he spoke to "white folks" - claims which he has denied
• He admitted saying the NAACP was "un-American" and "communist-inspired"
• He twice voted against legislation which would expand the definition of a hate crime to include offences based on sexual orientation
• He has voted against laws to curb domestic violence and sexual assault and fiercely opposes abortion rights

Here's a look at what to watch for in today's hearing:

·         Policing: Senator Sessions is expected to face questions about how he would handle law enforcement reform in the wake of mounting racial tension over police shootings across the country in cities like Ferguson, Baltimore and Chicago.

·         Immigration: The anti-immigration senator may also be grilled by both Republicans and Democrats about his plans for immigration enforcement. He has supported Mr Trump's plan to build a wall around the US-Mexican border and has argued for limiting legal immigration.

·         Racist claims: Senator Cory Booker said he would be "breaking a pretty long Senate tradition" by testifying with several other prominent African-American leaders against his colleague based on his civil rights voting record. Senator Sessions was turned down for a federal judgeship in 1989 after he was accused of making racist comments.

·         Marijuana: Senator Sessions opposes marijuana legalisation and has called it a "very real danger". Attitudes towards marijuana legalisation have shifted as it is now legal in 26 states and the District of Columbia, but remains illegal at the federal level.

Donald Trump's nominee for US attorney general is set to face sharp questions from the Senate Judiciary Committee this morning, kicking off the first of a busy week of confirmation hearings for the president-elect's cabinet.

Senator Jeff Sessions, a 69-year-old hardline conservative from Alabama, is due to testify at 9:30 EDT (14:30 GMT) before his colleagues, who will help determine whether he becomes the nation's next top lawyer.

The former prosecutor with 20 years in the Senate will be challenged to defend allegations of racism.

Who is Jeff Sessions?