Former White House counsel Don McGahn failed to appear Tuesday before a Congressional committee after President Donald Trump directed him to skip the hearing despite a subpoena issued for his testimony.

House Judiciary Committee Chairman Rep. Jerry Nadler, D-NY, said during Tuesday’s brief hearing that lawmakers were considering options to compel his testimony.

“McGahn has a legal obligation to be here,” Nadler said. “If he does not immediately correct his mistake, this committee will have no choice but to enforce the subpoena."

Update 10:45 a.m. EDT May 20: House Judiciary Committee Chairman Rep. Jerry Nadler, D-NY, said Tuesday that subpoenas from his committee, even when issued to a senior presidential advisor like McGahn, are not optional.

“Let me be clear,” Nadler said at Tuesday’s hearing, “This committee will hear Mr. McGahn’s testimony, even if we have to go to court to secure it.”

The Justice Department on Monday released a 15-page legal opinion stating that McGahn has no obligation to honor a congressional subpoena due to immunity granted to him as one of the president’s immediate advisers.

The ranking member of the House Judiciary Committee, Rep. Doug Collins, R-Ga., said Tuesday’s hearing was little more than "theater" put on by Democrats digging for nonexistent dirt in the wake of special counsel Robert Mueller’s 22-month investigation into Russian election meddling and its possible ties to Trump and his campaign officials.

“The majority claims we need to dig deeper than the two years of investigation by what is considered a prosecutorial dream team,” Collins said. “(Nadler) does not actually want information. He wants the fight, but not the truth.”

Update 10 a.m. EDT May 20:  The House Judiciary Committee is holding a hearing starting at 10 a.m. Tuesday about the report submitted earlier this year by special counsel Robert Mueller, who spent 22 months investigating Russian election interference and its possible ties to Trump and his campaign officials.

McGahn was subpoenaed to testify at the hearing, although he said Monday he would not appear after he was directed not to by Trump.

Update 10:45 p.m. EDT May 20: House Judiciary Chairman Jerry Nadler warned former White House counsel Don McGahn  that if he fails to appear at a hearing Tuesday morning "the Committee is prepared to use all enforcement mechanisms at its disposal."

In a letter to McGahn’s attorney, William Bruck, Nadler called Trump’s order for McGahn to ignore the subpoena from the committee to testify “unprecedented.”

He also said Trump’s order “does not excuse your (McGahn’s) obligation to appear before the Committee.”

“Although the Justice Department’s Office of Legal Counsel has produced an opinion purporting to excuse you (McGahn) from testifying, that opinion has no support in relevant case law, and its arguments have been flatly rejected by the courts,” Nadler said.

Nadler said the committee hearing will convene Tuesday morning, whether McGahn chooses to appear or not.

Update 8:40 p.m. EDT May 20: Despite a subpoena, former White House counsel Don McGahn has informed the House Judiciary Committee that he will not  appear at a hearing Tuesday, according to a report from The Hill.

McGahn's lawyer, William Bruck, sent a letter to Judiciary Chairman Jerry Nadler informing him that McGahn would not comply with the subpoena and would not attend to the hearing, The Hill reported.

The House Judiciary Committee subpoenaed McGahn and four other White House officials as part of an investigation into possible obstruction of justice, corruption and abuse of power charges, according to CNN.

Update 7:00 p.m. EDT May 20: President Donald Trump told reporters on his way to a rally in Pennsylvania Monday afternoon that he ordered former White House counsel Don McGahn to ignore a Congressional subpoena for the greater good of the presidency.

“As I understand it they're doing that for the office of the presidency for future presidents. As I understand it it's a very important precedent. The attorneys say they're doing it not for me, they're doing it for the future,” Trump said.

House Judiciary Committee Chairman Jerry Nadler said in a statement that the hearing will convene as planned, even though McGahn has been ordered not to testify

Nadler said McGahn witnessed "egregious" acts of obstruction to the Mueller investigation by Trump and that the president “clearly does not want the American people to hear firsthand about his alleged misconduct.”

“This move is just the latest act of obstruction from the White House that includes its blanket refusal to cooperate with this committee. It is also the latest example of this administration’s disdain for the law,” he said.

Original report: The committee is scheduled to hold a hearing starting at 10 a.m. Tuesday about the report submitted earlier this year by special counsel Robert Mueller, who spent 22 months investigating Russian election interference and its possible ties to Trump and his campaign officials. In the report, Mueller said his team found no evidence of collusion, but he declined to make a decision on whether there was enough evidence to charge Trump with obstruction of justice.

In an opinion released Monday, Justice Department officials said the president’s “immediate advisors” can’t be compelled to give congressional testimony due to the “fundamental workings of the separation of powers.”

“Because Congress may not constitutionally compel the former Counsel to testify about his official duties, he may not be civilly or criminally penalized for following a presidential directive not to appear,” the opinion stated.

In a statement released Monday afternoon, White House Press Secretary Sarah Huckabee Sanders pointed to a newly issued opinion and noted that “McGahn has been directed to act accordingly.”

“This action has been taken in order to ensure that future Presidents can effectively execute the responsibilities of the Office of the Presidency,” she said.

House Judiciary Committee Chairman Rep. Jerry Nadler, D-N.Y., issued a subpoena last month to compel McGahn's testimony. The committee was looking particularly at bringing in a member of Trump's staff with direct knowledge of his efforts to undermine the Mueller probe, CNN reported last month, citing an unidentified source.