Rep. Darrell Issa issued scathing conclusions Tuesday about Lois Lerner’s involvement in the Internal Revenue Service’s scrutiny of advocacy groups.

The California Republican and chairman of the House Oversight and Government Reform Committee released a 141-page report saying Lerner “led efforts to scrutinize conservative groups while working to maintain a veneer of objective enforcement.” He also accused her of obstructing the oversight committee’s investigation and misleading Congress.

The panel is considering whether to hold Lerner in contempt of Congress for refusing to answer questions about the IRS’s screening methods.

Lerner’s attorney, William Taylor, denied Tuesday that his client plotted against the groups.

“As we have said, the majority has no interest in the facts,” Taylor said. “The facts interfere with keeping the conspiracy theory alive through the election cycle. It would be interesting to know who with any knowledge of the facts says Ms. Lerner did these things. There is not such a person.”

E-mails in Issa’s report show that Lerner discussed launching a project to ensure that nonprofit advocacy groups complied with tax law, but they show no explicit directions to focus on conservative organizations.

An inspector general’s audit in May said that the IRS had wrongly targeted nonprofit groups but found no evidence of political motivation. It faulted mismanagement and a lack of clear directions for handling applications.

Issa’s report said Lerner was trying to undermine the Supreme Court’s Citizens United decision.

“The Supreme Court dealt a huge blow, overturning a 100-year-old precedent that basically corporations couldn’t give directly to political campaigns, and everyone is up in arms because they don’t like it,” Lerner said at a Duke University forum in 2010. “The Federal Election Commission can’t do anything about it. They want the IRS to fix it.”

Issa said Lerner made “false or misleading statements” to the panel by denying in February 2012 that the IRS changed its screening criteria and by saying the agency’s review methods did not exceed its usual standards.

The IG’s audit found that Ler­ner ordered her division to alter the screening criteria in June 2011 because they focused too much on groups’ policy positions. It also determined that the agency overreached in seeking donor information from nonprofit groups.

Other IRS officials told the panel they could not remember such previous donor requests.

Last week, Lerner refused for a second time to answer the committee’s questions, invoking her Fifth Amendment rights.

A frustrated Issa adjourned the hearing without input from Democrats, angering the ranking Democrat, Rep. Elijah E. Cummings (Md.). Issa cut off Cummings’s microphone but later apologized.

Cummings criticized Issa’s conclusions Tuesday, saying: “While there is certainly evidence of mismanagement at the IRS, this partisan Republican staff report identifies absolutely no evidence to support the central Republican allegations in this investigation — that the White House directed this activity or that it was politically motivated.”

Lerner retired in September.