(AP) – Dr. Anthony Fauci on Friday declined a request to appear voluntarily before a second Senate panel after majority Republicans on the Homeland Security Committee voted along partisan lines last week to hold the longtime infectious disease expert in contempt.

In a pointed letter to Sen. Ron Johnson, a Wisconsin Republican, a lawyer for the former director of the National Institute of Allergy and Infectious Diseases said any effort to compel him to appear before a Senate subcommittee, after a contentious July 29 hearing, would be to “impermissibly harass or degrade Dr. Fauci for political purposes.”

During the July hearing on his handling of the COVID-19 pandemic, Fauci invoked the Fifth Amendment right against self-incrimination 100 times, prompting the Aug. 6 contempt vote and setting up a referral to the Justice Department for potential investigation over whether he had properly exercised his constitutional rights.

Republican Sen. Rand Paul of Kentucky, the committee chairman who pressed for the contempt finding, said the constitutional protection did not apply because Democratic President Joe Biden had issued a preemptive pardon to Fauci, and he did not need to be concerned about potential prosecution.

Paul has long accused Fauci of misleading the public during the pandemic and the July hearing was the latest episode in his highly publicized confrontations with him. Paul has repeatedly called for Fauci to be prosecuted and imprisoned.

Johnson, chairman of the subcommittee on investigations, had sought to open a parallel avenue of congressional investigation about Fauci’s role in responding to the COVID-19 pandemic, including the safety and efficacy of the COVID-19 vaccines.