On Sunday, the two parties met to discuss Mr Musk's plan and were making progress, though there were still concerns. There is no certainty that they will achieve an agreement.
Mr Musk has insisted that his $54.20-per-share offer is his "best and final," and he has told Twitter Chairman Bret Taylor in recent days that he will not compromise on the price, according to some of the sources. The two parties were scheduled to discuss what Mr. Musk would pay if an agreed-upon agreement fell through before it could be completed.
Twitter is likely to comment on the deal when it reports first-quarter earnings on Thursday, if not sooner.
The board of directors of Twitter adopted a poison pill defense on April 15 to safeguard the company from Elon Musk. As a result, Twitter's planned "poison pill" against Musk's potential purchase is a device that could push the outspoken entrepreneur into talks.
Other Twitter shareholders would be able to buy shares at half-price, increasing the number of shares in circulation and diminishing Musk's power. It would be nearly hard for the Tesla executive to gain complete control of the company without spending far more than he had anticipated.
On the one hand, while the poison pill would prohibit Twitter shareholders from tendering their shares, the firm is "concerned" that if it is revealed to be going against the wishes of many of its shareholders, its negotiating position would be significantly weakened.
With shareholders directly approaching the board, the pendulum is swinging in Musk's favor, and it appears that the poison pill wasn't too tricky for the Tesla CEO to swallow.