(Reuters) - Former top legal executives at large companies including Microsoft ( MSFT ), Intel ( INTC ) and Eli Lilly ( LLY ) submitted a legal brief on Tuesday accusing U.S. President Donald Trump of undermining the rule of law and threatening American businesses with his executive orders targeting law firms.

The 67 mostly former general counsels said Trump's orders violate the U.S. Constitution and "hijack" the relationships companies have with their outside lawyers.

The friend-of-the-court brief was filed to support Perkins Coie in its lawsuit against the Trump administration over an executive order that suspended its lawyers' access to government buildings and officials and threatened to cancel federal contracts held by the firm's clients.

"The order does not merely punish a single law firm and its thousands of employees; it erodes the foundation of legal representation by counsel of choice, uses federal contracts to coerce political loyalty, and conscripts private businesses to settle the president's political scores," the brief said. "Its message is clear: hire the wrong lawyers, or take the wrong public stance, and your company will be punished."

Trump issued similar executive orders against law firms WilmerHale and Jenner & Block. All three firms have sued the administration and won rulings temporarily blocking Trump's orders.

Signatories to Tuesday's brief included Ivan Fong, the former chief legal and policy officer of 3M and current general counsel of Medtronic. Former Verizon general counsel Randal Milch signed, as did Dorian Daley, who was previously Oracle's top lawyer.

Milch declined to comment. Fong and Daley did not immediately respond to requests for comment.

Microsoft ( MSFT ), Medtronic, Verizon, Oracle and Eli Lilly ( LLY ) also did not immediately respond to requests for comment. 3M and Intel ( INTC ) declined to comment.

White House spokeswoman Karoline Leavitt said in a statement Trump is "determined to end the weaponization of 'Big Law' against Americans for their political beliefs."

Four days earlier, 504 law firms filed their own brief backing Perkins Coie's case and denouncing Trump's executive orders. Most of the largest U.S. firms did not join that brief.

A Perkins Coie spokesperson said the firm was grateful for the outside support it has received.

Another firm targeted by Trump in an executive order, Paul Weiss, reached a deal with him to rescind it. Three other firms - Milbank, Willkie Farr & Gallagher and Skadden Arps - have come to agreements with Trump without being hit with an order against them.

The firms each pledged tens of millions of dollars in free legal services to support causes favored by the White House and agreed not to engage in discriminatory employment practices. The firms said in public statements the deals were consistent with their principles, including their political independence.

Trump has targeted law firms that represented clients who have challenged his policies in court, employed lawyers involved in prosecutorial investigations against Trump, or represent people who previously have investigated him. His orders also have faulted the firms for workplace diversity policies.

"General counsel and other corporate leaders must now assess not just the skill, expertise, and trust they have in counsel, but also whether those lawyers work at law firms that the president may seek to discredit or destroy," Tuesday's brief said.