Sally Yates was urged to remain independent of President - by Donald Trump's own Attorney General

Donald Trump’s pick for Attorney General repeatedly pressed Sally Yates about the need for the nation's top lawyer to keep independence from the White House, according to footage from her 2015 confirmation hearing.

Ms Yates – who was acting as Attorney General during the transition to the Trump administration – was fired on Monday night after she told justice department lawyers not to defend Mr Trump’s "travel ban".

She said she was concerned the executive order, which stops migrants from seven Muslim-majority countries entering the US, was not legally sound.

In a statement, the White House said Ms Yates had been "insubordinate" and had "betrayed" the department.

Jeff Sessions, who is expected to be confirmed as Attorney General by a committee on Tuesday, is shown in the 2015 footage questioning Ms Yates on whether she would “say no” and continue to give impartial legal advice if the President asked for “something improper”.

“You have to watch out because people will be asking you to do things, you just need to say no about," he said, asking: “You think the Attorney General has a responsibility to say no to the President if he asks for something that’s improper?"

“A lot of people have defended the [Loretta] Lynch nomination, for example, by saying: ‘[Obama] appoints somebody who’s going to execute his views, what’s wrong with that?’

“But if the views a president wants to execute are unlawful, should the Attorney General or the Deputy Attorney General say no?

In response, Ms Yates said: “I believe that the Attorney General or the Deputy Attorney General has an obligation to follow the law and the constitution and to give their independent legal advice to the president.”

Critics have taken to social media to claim Mr Sessions' sustained questioning proves the Trump administration was hypocritical to fire Ms Yates.

In her letter to justice department lawyers, the acting Attorney General said: “I am responsible for ensuring that the positions we take in court remain consistent with this institution’s solemn obligation to always seek justice and stand for what is right.

“At present I am not convinced that the defence of the executive order is consistent with these responsibilities nor am I convinced that the executive order is lawful.”

Prosecutor Dana Boente has taken up the role until Mr Sessions is confirmed by the Senate, according to the White House.

The White House press office quoted Mr Boente as saying: “I am honoured to serve President Trump in this role until Senator Sessions is confirmed.

“I will defend and enforce the laws of our country to ensure that our people and our nation are protected.”

The Associated Press reported on Tuesday that Mr Boente had overturned Ms Yates' instruction and directed justice department lawyers to defend Mr Trump’s executive order on immigration and refugees.

The travel ban order halts America's refugee program for four months, indefinitely bans all those from war-torn Syria and freezes immigration from Iraq, Syria, Iran, Sudan, Libya, Somalia and Yemen.

White House spokesman Sean Spicer challenged officials who opposed to the measure to resign, saying: “They should either get with the program or they can go.”

Mr Sessions, who will take up the Attorney General position after he is confirmed by the Senate, is a longtime ally of the President.

He has been dogged by claims of racism and bigotry throughout his career and was denied a federal judgeship 30 years ago due to allegations of racial discrimination.

Before being rejected from the position, the Senate Judiciary Committee heard several allegations accusing Mr Sessions of racism.

In one incident, he allegedly referred to a black local government official as “the n*****”, while senators also heard that Mr Sessions had called a black official in his office “boy” and instructed him to be careful what he said to white people.

Mr Sessions rejected the racism allegations, telling the committee: “I deny as strongly as I can express it that I am insensitive to the concerns of blacks.”

Ms Yates served as deputy Attorney General in the Obama administration and was asked by the Trump team to stay on to smooth the transition of power.

A statement from the White House said: “Ms Yates is an Obama administration appointee who is weak on borders and very weak on illegal immigration.

“It is time to get serious about protecting our country. Calling for tougher vetting for individuals travelling from seven dangerous places is not extreme.

“It is reasonable and necessary to protect our country.”