Illustration by Kristen Radtke / The Verge; Getty Images

There has been an unexpected shake-up on the board of directors of the company.

On Wednesday, Silver Lake co-CEO Egon Durban failed to win the support of a majority of the shareholders of the micro-blogging site to remain on the board for another term after two investor groups raised concerns that he sits on the board of too many public companies. The other board members refused to accept his resignation and instead forged an agreement for him to resign from two other board seats over the course of the next year.

“accepting Mr. Durban’s tendered resignation at this time is not in the best interests of the Company”

In the filing, the board takes note of Silver Lake's ongoing stake in Twitter and says that Mr. Durban has strengthened its ability to oversee the Company's long-term value creation strategy.

The dust-up is notable because of the close ties between the city and Musk. As co-CEO of the private equity firm Silver Lake, Durban has worked with Musk on a number of major equity deals. As a result, he is seen as one of Musk's closest allies on the board and a crucial figure as Musk's proposed buyout of the company limps towards completion.

In an effort to focus more on his payments and cryptocurrencies company, Block, Jack Dorsey, the former CEO of Twitter, left the company's board on Monday.

On April 25th, Musk entered into an agreement to buy all of the outstanding shares of the company at a price of $54.20, but in recent weeks, he has sent mixed messages about whether he will make good on the deal. On May 13th, Musk said that the deal was on hold due to an investigation into bot activity on the platform.

Many have interpreted the move as an effort to negotiate a lower price for the company, a scenario Musk has described as "not out of the question." The board of directors is tasked with protecting the interests of shareholders.

A proposed class-action lawsuit was announced earlier this week to address the same concerns, as well as allegations that Musk made false and misleading statements that drove down the value of the company's stock. There is a persistent skepticism that the deal will proceed as agreed.