Billionaire Elon Musk wants to terminate his $44 billion deal to buy Twitter, according to a letter sent by a lawyer on his behalf to the firm’s chief legal officer Friday.

However, Twitter’s board chair Bret Taylor said the company is still dedicated to closing the deal as per the agreement, even if they have to pursue legal action to enforce the agreement.

“We are confident we will prevail in the Delaware Court of Chancery,” Taylor wrote.

Twitter shares plunged 6% after hours on Friday.

In the letter, disclosed in a Securities and Exchange Commission filing, Skadden Arps attorney Mike Ringler said that “Twitter has not complied with its contractual obligations.”

Ringler argued that Twitter did not give Musk the relevant business information he requested, as Ringler said the contract would require. Musk has previously announced he wanted to assess Twitter’s claims that about 5% of its monetizable daily active users (mDAUs) are spam accounts.

“Twitter has failed or refused to provide this information,” Ringler claimed. “Sometimes Twitter has ignored Mr. Musk’s requests, sometimes it has rejected them for reasons that appear to be unjustified, and sometimes it has claimed to comply while giving Mr. Musk incomplete or unusable information.”

Ringler also claimed in the letter that Twitter breached the merger agreement because it allegedly contains “materially inaccurate representations.” 

“While this analysis remains ongoing, all indications suggest that several of Twitter’s public disclosures regarding its mDAUs are either false or materially misleading,” Ringer alleged.

“Despite public speculation on this point, Mr. Musk did not waive his right to review Twitter’s data and information simply because he chose not to seek this data and information before entering into the Merger Agreement,” Ringer added. “In fact, he negotiated access and information rights within the Merger Agreement precisely so that he could review data and information that is important to Twitter’s business before financing and completing the transaction.”

He also claimed Twitter breached its obligations under the agreement to get Musk’s consent before changing its ordinary course of business, pointing to recent layoffs at the company.