A row over the decision by a leading New York university to refuse playwright Tony Kushner an honorary degree due to accusations he was too critical of Israel has deepened as several high profile honorary degree holders renounced their own awards.

Kushner, who wrote the Pulitzer prize-winning Angels in America, was set to get an honorary degree from John Jay College, a campus of City University of New York. But his name was removed from a list of other intended recipients after a CUNY trustee, pro-Israel activist Jeffrey Wiesenfeld, spoke out against it.

Wiesenfeld accused Kushner of being critical of the Israeli army, supportive of a boycott of the country and of saying that Israel had been founded partly as a result of ethnic cleansing. In an open letter to CUNY Kushner responded angrily, denying the allegations, accusing Wiesenfeld of slander and saying he was "proud to be Jewish".

Now, in the wake of Kushner's letter, at least three prominent previous recipients have declared they no longer want their honorary degrees from the university. Barbara Ehrenreich, an acclaimed activist journalist, issued a statement saying she had renounced her 2004 award. "Please expunge me from your record of past honorees," she said. She was joined by Michael Cunningham, who also has won a Pulitzer, for his book The Hours, and was given an honorary degree in 2009. "I was shocked and dismayed to hear about the treatment Tony Kushner received at the hands of the CUNY board of trustees," he said in a statement.

He criticised the university's decision. "To deny him an honorary degree because certain members of the board disagree with some of his political views is a chilling indictment of the freedom of expression CUNY has always championed."

Yeshiva University historian Ellen Schrecker also wrote to CUNY to protest and to ask how she could return her own honorary degree.

So far the university has issued little detailed public comment on the growing row and Kushner has said in interviews that he would no longer accept the degree if the decision were reversed.

A CUNY statement said that the university's board operated independently in making decisions and offered no apology. "The board's actions, however, should not be interpreted as reflecting on Mr Kushner's accomplishments and we regret any such misunderstanding," it added.

Meanwhile, the decision was condemned even by CUNY's own faculty union. Union president Dr Barbara Bowen said the vote to not give Kushner an award was "perverse" and aimed at cutting off genuine political and intellectual debate at the university. "The trustees' craven decision is an offence against open intellectual discussion and freedom of thought. It dishonors our university, and the values for which we ought to stand," she said.

The controversy is not the first of its kind to involve Wiesenfeld. In February Brooklyn College, another CUNY campus, fired Kristofer Petersen-Overton from a one semester teaching post after objections were raised by Wiesenfeld and others about his views on Israel and the Middle East. In that case Wiesenfeld directly lobbied chancellor, Matthew Goldstein, along with local Brooklyn politician Dov Hikind, to get the academic removed from his post.

But after a furious row in the media Petersen-Overton was reappointed. For the time being Wiesenfeld is sticking to his guns. On a blog post at the Jewish news website the Algemeiner he called Kushner an "extremist".

"The denial of the honorary degree to Mr Kushner, despite his protestations was a reflection of his long-held radical sentiments," he said.

Kushner, whose latest play is currently playing on Broadway, is one of the most famous and acclaimed names in modern American theatre. Angels in America, which is his best known piece, dealt with the Aids crisis in 1980s America.

Ironically, people being persecuted for their political views figures in the play and is also a re-occurring theme elsewhere in his work.

• This article was amended on 9 May 2011. The original named a novel as Paul Angels in America. It also used the spelling Kristopher Petersen-Overton. This has been corrected.