A female litigation partner at Chadbourne & Parke who last year filed a $100m gender discrimination suit against the firm has been expelled from its partnership.

A partners' meeting resulted in 70 partners voting in favour of Kerrie Campbell's expulsion, with Campbell the only dissenting partner, although several partners abstained. A roll call of partners was called in order of descending points in the firm's partnership.

"At a meeting of the full partnership today, the partners of Chadbourne & Parke voted to terminate Kerrie Campbell's partnership interest," a firm spokesman said. "Ms Campbell attended, spoke at, fully participated and voted as a partner at the meeting. No partner other than Ms Campbell voted against the motion to expel."

Campbell's lead lawyer, David Sanford of Sanford Heisler Sharp, called Chadbourne's action the latest in a series of retaliatory measures taken against Campbell and vowed to file an amended complaint against the firm.

"Chadbourne's vote to expel Ms Campbell was based on biased and incomplete information," Sanford said in a statement. "The result of the vote is, therefore, not surprising… A trial in this case will bring to light the facts and we are confident that the truth will emerge. This case, ultimately, will not be about Kerrie Campbell alone. It will be about three class representatives, all female partners, with nearly 50 years of collective experience at Chadbourne, who will prove a systematic pattern of discrimination in pay at the firm directed against female partners."

An initial partnership vote scheduled for Wednesday (19 April) was postponed, giving Campbell a temporary reprieve as she awaited the fate of her future at Chadbourne. While the delay had some speculating about settlement talks – Sanford has previously acknowledged such discussions – the postponement appeared to be procedural.

"Chadbourne's partners met today to address the issue of expelling Kerrie Campbell from the partnership," a firm spokesman said. "Ms Campbell was present at the meeting and spoke on her own behalf. The partners will now make their own decision based on Ms Campbell's past performance and conduct at Chadbourne and also the discussions held today. The vote on the motion will take place on Thursday morning so partners may consider the issue thoroughly."

Campbell, who earlier this week unsuccessfully sought to have a federal judge in New York block the partnership vote, had written a memorandum to all Chadbourne partners urging them to vote against what she called a decision by the firm's management committee to expel her from the partnership. Campbell noted that she is currently on leave recovering from a medical issue, and that as the sole breadwinner for her family it would be financially ruinous for her to be struck from the partnership, even though the firm has already allegedly slashed her pay.

The American Lawyer reported earlier this month on Chadbourne's decision to call a partners' meeting to vote on whether to eject Campbell from the partnership. The firm is poised to combine with Norton Rose Fulbright within the next two months. Lawyers for Campbell and two other former Chadbourne partners suing the firm – of counsel and ex-product liability leader Mary Yelenick, and former Kiev office leader Jaroslawa Zelinsky Johnson – have said that Norton Rose Fulbright could be drawn into the case.

In her three-page memo to Chadbourne partners, Campbell sought to preserve what remained of her status at the New York firm, which she joined in January 2014 from Manatt Phelps & Phillips in a move brokered by legal recruitment shop Sitcov Director. Before choosing redress through the courts, Campbell claimed that she raised internally her concerns about pay equity, first to former Washington DC office managing partner Dana Frix, and then with broader firm management. She wrote that other female partners at Chadbourne – including Yelenick, Johnson, ex-emerging company and venture capital chair Lori Hoberman, and former disputes partner Melanie Willems – had previously done the same.

Willems and Hoberman both joined Chadbourne in 2010. Hoberman, who came aboard from Fish & Richardson, did not return a request for comment. She left Chadbourne in late 2014 to start her own firm in New York. Willems left in late 2013 for Andrews Kurth, now called Andrews Kurth Kenyon after the recent completion of a merger. Willems subsequently sued Chadbourne over the return of $127,000 in capital.

Willems, now head of international arbitration at Andrews Kurth Kenyon and the managing partner of its London office, also did not return a request for comment about Campbell and Chadbourne. Frix, a former chair of Chadbourne's telecoms, media and technology practice, left Chadbourne almost a year ago to start his own firm. He declined to discuss Campbell or his former firm, which he joined in 2002 from O'Melveny & Myers.

Campbell and her legal team at Sanford Heisler Sharp are working with mediator Dina Jansenson at JAMS in the litigation with Chadbourne. The latter has asserted that the plaintiffs' claims are meritless.

Chadbourne refutes Campbell's allegations of retaliation and gender bias by arguing that she and her fellow plaintiffs were compensated according to their individual contributions to the firm. Chadbourne, which has questioned Campbell's personal and professional conduct, is also raising a more technical defence by asking a court to rule that as current and former partners, the plaintiffs should not be classified as employees under the Equal Pay Act.

Proskauer Rose is advising Chadbourne in the gender bias suit brought by Campbell, Yelenick and Johnson.