Washington (AFP) - The US Supreme Court's Chief Justice John Roberts is refusing to testify in Congress about business dealings by two conservative justices and lavish gifts one received that have raised ethics issues.
Roberts cited "separation of powers concerns and the importance of preserving judicial independence" in declining the committee's invitation in a letter dated Tuesday to the Senate Judiciary Committee.
He included a copy of court ethics guidelines and a statement signed by the nine justices in which they "reaffirm and restate foundational ethics principles and practices."
But Roberts made no direct reference to the controversy engulfing the court's most senior justice, Clarence Thomas, that Thomas and his wife Ginni received lavish gifts and took vacations worth millions of dollars with property billionaire Harlan Crow.
Thomas did not report those gifts, which included a flight on Crow's private jet to Indonesia for an island-hopping cruise on Crow's 162-foot (49 meter) yacht, according to the independent ProPublica news outlet.
Nor did he report regularly vacationing at luxury resorts owned by Crow, or that the tycoon bought properties in Savannah, Georgia from the justice, including the home occupied by Thomas's mother, according to ProPublica.
Roberts's refusal to testify also followed a report by Politico that Justice Neil Gorsuch, just after being confirmed to the court in 2017, sold a large rural Colorado property to the head of Greenberg Traurig, a major US law firm which regularly handles cases before the high court.
Gorsuch had tried without success to sell the property for two years before joining the court, and he did not disclose the buyer on his personal disclosure reports, according to Politico.
On April 20, Senate Judiciary Committee chair Dick Durbin asked Roberts to appear on May 2 to discuss ethics issues around the court.
Since the last time justices appeared before Congress in 2011, also on ethics questions, "there has been a steady stream of revelations regarding justices falling short of the ethical standards expected," wrote Durbin.
The 2011 appearance by two justices was also sparked by allegations of Thomas and his wife benefitting financially from relations with Crow and other powerful Republican donors.
A specific focus then was Crow's donation of $500,000 to fund Ginni Thomas's new Liberty Central advocacy group.
Ginni Thomas is currently under scrutiny for her role in former president Donald Trump's late-2020 campaign claiming, without evidence, that Joe Biden's election victory over him was fraudulent.