"It would be disingenuous for me to suggest to this committee that there is support for the bill as amended," he said.
The chairman of Rutgers' less powerful board of trustees told the committee that her membership also opposes Sweeney's proposal.
The committee voted, 7-5, to send the amended bill to the full Assembly.
Informed of Harvey's testimony, Sweeney said: "He said, if you would amend this bill, in this fashion, that he would publicly support it. I took him at his word.
"You shouldn't tell somebody one thing and then say something to other people differently," Sweeney said.
Sweeney's bill would increase the board from 15 members to 19. Ten would be appointed by the governor and nine by the board of trustees, which serves in a largely advisory capacity.
Last year, Sweeney tried to abolish that 59-member board, which he has described as unwieldy.
Sweeney said his proposal would help modernize Rutgers and better reflect its expansion into health sciences. Two of the four new appointees to the board of governors would need medical expertise.
The amended version eliminates provisions granting the Senate president and Assembly speaker one appointment each to the governing board. Instead, all four new members would be appointed by the governor - a nod to a nonpartisan Office of Legislative Services memo that suggested direct legislative appointments could raise constitutional questions regarding separation of powers. The amendments require the two legislative leaders to recommend appointments to the governor.
Two of the appointees would be chosen by the governor from among the trustees, to serve on both boards, a sign of compromise with trustees, who have vocally opposed the legislation.
Rutgers activists had worried that Sweeney's bill would tilt the board's balance of power in favor of political appointees.
It was unclear whether the bill, even as amended, could overcome legal objections. The Rutgers boards have explored the possibility of suing. Sweeney said Thursday that he did not think the matter would end up in court.
The Office of Legislative Services said in the memo issued Wednesday that changes to Rutgers' governance without the approval of both boards could prompt a legal challenge.
The 1956 law that made Rutgers the state university of New Jersey established the board of governors and created a contract between the trustees and the state, the memo said. Changing the board without the trustees' consent could breach that contract, violating the U.S. and New Jersey constitutions, the memo said.
Sweeney's original bill was "so egregiously flawed that it had to be changed," Senate Minority Leader Thomas H. Kean Jr. (R., Union) said Thursday.
To that end, Kean said, he voted to amend the bill. The amendments passed on a 22-0 procedural vote; Sweeney is expected to schedule a vote on the bill before the end of the month.
Kean said Sweeney's proposal still does nothing to address problems cited in a Rutgers report on the university's governance.
It questioned the qualifications of political appointees on the governing board.
The Senate president said the report, which was provided to the Legislature only after he threatened to file a public-records request to obtain it, showed the need for change.
"Even their own report says they need to restructure the governance at the school," he said.
Any such governance change would need the formal consent of the Rutgers boards to be constitutional, advocates say.
"Even if they like it, they would still have to consent," said Allan Stein, a law professor at Rutgers-Camden who has opposed the bill. Stein cited the example of the 2012 higher education restructuring, which the boards both approved and a court signed off on.
"Even if they were to say, 'Let's add four members, two from the trustees and two from gubernatorial appointments,' I think that would require approval, because that's a change to the structure," he said.