A Republican-controlled US Senate committee voted to hold Dr Anthony Fauci in contempt of Congress after the veteran public health official repeatedly pleaded the fifth amendment to parry a hostile inquisition into his stewardship of the response to the Covid-19 pandemic.

Fauci, the former director of National Institute of Allergy and Infectious Diseases (Niaid), who led the agency for 38 years before retiring in 2022, gave the same response to dozens of questions while refusing to give clarifying answers during a tense hearing last week, citing his constitutional protections.

The Senate homeland security and government affairs committee voted in favor of referring a potential criminal case against Fauci to the US Department of Justice.

The vote was condemned as “shameful” and a “crude political stunt” by Fauci’s lawyer, David Schertler, who was forcibly ejected from last week’s hearing when he tried to speak on behalf of his client.

The committee is chaired by Republican Kentucky senator Rand Paul, whom Fauci last week accused of having an “unhinged obsession” with him as he refused to answer questions at the hearing.

Paul insisted on Thursday that he wasn’t trying to entrap Fauci. “He had no liability if he told the truth,” Paul said.

“The chair directed Anthony Fauci to answer. He refused,” Paul said in his opening statement. “That is what we are voting on today – not his opinions, not his policies, not anything he said from the podium six years ago.

“We are voting on whether a witness who has received the benefit of a sweeping federal pardon can be ordered by this committee to answer questions and then defy that order without consequence.”

But top Democrats criticized the Republicans-led process. Michigan senator Gary Peters, the ranking Democrat on the Senate panel, argued that the drive to subpoena Fauci, and now to hold him in contempt, accomplished nothing to advance public health.

Paul’s work amounts to “a one-sided investigation and a rushed process … that could harm our ability to conduct future investigations”, said Peters.

While a contempt referral must typically be approved by the full Senate after a congressional committee, this would likely require a 60-vote majority – requiring Democratic support.

Paul acknowledged this standard path on Wednesday, but said he did not “want to waste time” moving the matter to a vote of the full Senate. He previously suggested during a Fox News interview that ​he could send the referral ​directly to the justice department, with a legal brief.

Peters warned that bypassing a full Senate vote might not be legally valid and said punishing Fauci for exercising his fifth amendment rights could deter future witnesses from giving congressional testimony.

“Future witnesses will argue that appearing before Congress exposes them to punishment regardless of whether they comply with a subpoena and invoke a constitutional protection,” he said.

The fifth amendment is enshrined in the US constitution as a protective measure intended to save individuals from being forced to incriminate themselves when under investigation or asked to provide testimony.

The evening before the vote, it emerged that the US Department of Health and Human Services had provided a copy of Fauci’s phone to a Senate subcommittee. “Hopefully, this device will address many of the questions he refused to answer at last week’s hearing,” Republican Ron Johnson of Wisconsin, the subcommittee’s chair, wrote on social media.

Fauci, 85, who was pardoned by Joe Biden at the end of his presidency, declined to answer questions after accusing Paul of harboring a goal of “embarrassing and intimidating me” and of putting him “behind bars” because of his leading role in urging widespread restrictions, including masking and social distancing, to combat the pandemic.

The senator has long accused Fauci of deliberately downplaying the possibility that the virus of originated from a research laboratory in the Chinese city of Wuhan, rather than jumping from an animal to humans in a wet market, as most scientists believe.

“Although it pains me to do so, because of the respect I have for the legislative branch of government and my decades-long record of cooperating with Congress, under the advice of my attorneys I will invoke my right under the fifth amendment of the constitution to refrain from answering your questions,” Fauci said during the hearing.

Thereafter, he warded off all subsequent questions with identical answers that invoked the fifth amendment, enraging his Republican critics.

“On the advice of counsel, I respectfully decline to answer based upon my rights under the fifth amendment of the constitution,” he said, in an undeviating answer to different questions.

Paul – who had subpoenaed Fauci to appear – warned him during the hearing that his stance would have “repercussions”.

Later, he told him: “Because you refuse to answer, citing a privilege that is unsupported because of your pardon, and after being denied to do so, this committee has scheduled a vote next week on a resolution certifying your contempt.”

It is unclear whether a vote in favor of contempt will have legal force.

According to the constitution, the fifth amendment guarantees that no individual “shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law”.

The US supreme court has confirmed in several decisions since 1955 that witnesses can invoke it in congressional investigations, according to the Library of Congress.

“Although the [Fifth] amendment’s protection expressly refers to criminal cases[s], the Court has nevertheless found the privilege against self-incrimination to be available to a witness appearing before a congressional committee,” the library’s annotated interpretation of the constitution states.

Paul has insisted Fauci is precluded from pleading the fifth, however, on the grounds that the preemptive pardon Biden granted him means he cannot be prosecuted for any of the matters senators were asking him about.

Paul argued that Fauci’s refusal to answer could lead to criminal prosecution for contempt of Congress or obstructing a congressional proceeding.

Federal law makes it a crime for witnesses to “willfully” refuse to answer questions when called to give congressional testimony. A separate law makes it illegal to obstruct an investigation by a congressional committee.

Fauci’s lawyers have argued that he is on unassailable legal grounds by pleading the amendment.

“For years, senator Paul has proclaimed to anyone who would listen that Dr Fauci should be prosecuted and put in prison,” Schertler, Fauci’s legal counsel, said on Thursday. “Dr Fauci has committed no crime – and senator Paul knows it.

“Today’s resolution is a continuation of Senator Paul’s personal vendetta against Dr Fauci, who spent 50 years in public health and has saved countless lives. It is shameful and wrong that Senator Paul is abusing his power by trying to weaponize the justice department against an honorable public servant.”

Robert Mackey contributed reporting