A former White House aide is defying a request to testify before the US Congress.

Democrats in the House of Representatives are facing another attempt by President Donald Trump to stonewall their investigations after instructing former White House counsel Donald McGahn to defy his subpoena.

Donald Trump
Donald Trump has said his administration will fight every subpoena (AP Photo/Manuel Balce Ceneta)

A lawyer for Mr McGahn said he would follow the president’s directive and skip the House Judiciary hearing, leaving the Democrats without another witness.

House speaker Nancy Pelosi, backed by House Judiciary Committee chairman Jerrold Nadler, is taking a step-by-step approach to the confrontations with Mr Trump. Mr Nadler said the committee would vote to hold Mr McGahn in contempt, and take the issue to court.

Mr Nadler warned McGahn in a letter on the eve of the hearing: “You face serious consequences if you do not appear.”

Democrats are encouraged by an early success on that route as a federal judge ruled against Mr Trump on Monday in a financial records dispute with Congress.

But that has not been swift enough for some members of the Judiciary panel who feel that Ms Pelosi should be more aggressive and launch impeachment hearings that would make it easier to get information from the administration. Such hearings would give Democrats more standing in court and could stop short of a vote to remove the president.

The issue was raised in a meeting among top Democrats where some members confronted Ms Pelosi about opening up the impeachment hearings.

Maryland representative Jamie Raskin made the case that launching an impeachment inquiry would consolidate the Trump investigations as Democrats try to keep focus on their other work.

Ms Pelosi replied that several committees are doing investigations already and they had already been successful in one court case.

But the members, several of whom have spoken publicly about the need to be more aggressive with Mr Trump, are increasingly impatient with the careful approach.

In the hours after the discussion, Ms Pelosi and Mr Nadler met privately. Shortly after emerging from that meeting, Mr Nadler said “it’s possible” when asked about impeachment hearings. But he noted that Democrats had won a court victory without having to take that step.

“The president’s continuing lawless conduct is making it harder and harder to rule out impeachment or any other enforcement action,” Mr Nadler said.

Mr McGahn’s refusal to testify is the latest of several moves to block Democratic investigations by Mr Trump, who has said his administration will fight “all of the subpoenas”.

The Judiciary committee voted to hold attorney general William Barr in contempt earlier this month after he declined to provide an unredacted version of special counsel Robert Mueller’s report.

And the House intelligence committee is expected to take a vote on a separate “enforcement action” against the Justice Department this week after Mr Barr declined a similar request from that panel.

Mr McGahn was a key figure in Mr Mueller’s investigation, describing ways in which the president sought to curtail that federal probe. Democrats have hoped to question him as a way to focus attention on Mr Mueller’s findings and further investigate whether Mr Trump obstructed justice.