In a closed-door hearing - but with a live broadcast - former FBI director James Comey will respond tomorrow to the Senate Intelligence Committee's questioning of his statements against President Trump.

According to White House spokeswoman Sarah Huckabee, President Donald Trump "will not assert his executive privilege to prevent the former director from testifying at the Capitol," which would allow a public hearing on the alleged obstruction of the law committed by the president.

Both Democrats and Republicans have called for Comey’s official testimony, asserting, "it would be more helpful for the president to get all that information," Republican Senator Roy Blunt told Fox News Sunday.

Since being sworn in as president, Donald Trump attempted to approach the then-director of the FBI, who said the president would have asked for "loyalty" during a dinner at the White House on January 27.

Comey's investigation of alleged Moscow interventions in internal affairs raised pressure for the dismissal of National Security Director Michael Flynn, after it was made public his promise to the Russian ambassador about a withdrawal of sanctions to Moscow during the new administration.

Subsequently, and as Comey said after his dismissal, on February 14 the president would have summoned him to the White House to ask him to abandon the investigation on Flynn, who was at the center of the inquiries into possible links between Trump's advisers and Russia.

Calling for misbehavior in the investigation of Hillary Clinton's emails during the 2016 presidential campaign, Donald Trump decided to fire Comey on May 9, taking the director by surprise.

In an interview with NBC's Lester Holt, Trump asserted that Comey's dismissal was due to his frustration with "that Russian thing."

Among the President's inconsistencies and media and Democratic pressure, the Justice Department finally named former FBI Director Robert Mueller on May 17 as special adviser to oversee the FBI's investigation into Russian intervention in the presidential election.

Mueller's investigation has surrounded the president in recent weeks, when it included Jared Krushner - Trump's son-in-law, as Krushner would have met with the Russian ambassador in Washington during the month of December and would have very close ties with the Russian bank Vnesheconombank, which "has been subject to US sanctions for Russian interference in Ukraine," according to the Spanish newspaper El País.

Former Senator and now Attorney General Jeff Sessions has joined the controversy, when he offered to step down after "heated discussions" with President Trump, asserting that "he needed freedom to do his job."

The circumstance of the relationship between Sessions and Trump has been made public again by a Washington Post article that says, according to reports from two people close to the White House, that at some point in recent months the Attorney General offered his resignation.

After the same media reported on the undisclosed meetings between Sessions and the Russian ambassador Sergey Kislyak, Sessions had to recuse himself from the Russia investigation, leaving the president alone facing the FBI’s investigations, which would have increased discontent between the Prosecutor and Trump.

Also, former FBI director James Comey would have asked Sessions not to leave him alone with President Trump during the private meeting in the White House because he believed the attorney general should protect the FBI from the influence of the White House. On the contrary, Sessions added to the recommendation of Comey's dismissal.

Tomorrow the Senate Intelligence Committee is expected to question Comey about his dismissal and the Russian investigation, with special emphasis on the memorandums the former director says he has written after his talks with the president.

While the former director is unlikely to make a direct accusation of Trump's obstruction of justice, he is expected to detail each of his encounters and to provide the evidence that supports his statements.