As the June 1 date for shareholders of Alpha Natural Resources and Massey Energy to vote on Alpha’s takeover of Massey, litigation over the potential $8 billion deal is definitely heating up.

We reported earlier today on a lawsuit filed in Boone County by families of some of the miners who died in Massey’s Upper Big Branch Mine Disaster related to the proposed purchase of Massey by Alpha.  Basically, this suit alleges that the transaction is a great deal for Massey insiders — who stand to profit greatly from it — and puts at risk the ability of the victims’ families to recover from lawsuits over the April 5, 2010, explosion.  The suit alleges:

[Massey] is a corporation with considerable assets, including some of the best coal reserves in the central Appalachian region.

As a result of the misconduct and mismanagement of the insider defendants… all assets of [Massey] are being transferred to Alpha in the merger. In doing so, the insider defendants, as well as other members of management, including former CEO Don Blankenship, are liquidating risk into cash and are able to walk away from the merger with substantial amounts of cash while the plaintiff creditors will have nothing more than unsecured claims against a highly leveraged, cash-poor company.

And over at NPR, Howard Berkes reported today on what he called “last-ditch attempts by some Massey shareholders to block the deal.

Howard explained:

The lawsuits are so-called “derivative” suits in which shareholders assert they must sue on behalf of the company, and to protect the company’s value, because of alleged misbehavior by the directors and officers.

UPDATED: The Wednesday hearing referenced by NPR has been postponed, according to the office of Kanawha Circuit Judge Charles King.

The hearings in West Virginia Wednesday and Delaware Thursday seek preliminary injunctions blocking the merger, which is expected to be approved at shareholders meetings June 1.

Most of the court documents in both cases are sealed but NPR has obtained subpoenas issued to former Massey CEO Don Blankenship and current Chief Operating Officer Chris Adkins. Both involve appearances at Wednesday’s hearing in Kanawha County Circuit Court in Charleston, West Virginia.

Some lawsuits by shareholders were filed prior to the Upper Big Branch disaster and settled, while others were filed just after the disaster, and still more have been filed directly regarding the proposed deal with Alpha. A rundown of them all is available in Massey’s most recent quarterly report to shareholders and the U.S. Securities and Exchange Commission.

And, as SEC filings continue to pile in regarding the merger, some are providing more details about Blankenship’s departure from Massey. One in particular is interesting:

The plaintiffs in In re Massey Energy Company Derivative and Class Action Litigation filed a submission on May 15, 2011, in support of their request for equitable relief, including a preliminary injunction enjoining the consummation of the proposed merger of Massey Energy Company (Massey) and Mountain Merger Sub, Inc., a wholly owned subsidiary of Alpha Natural Resources, Inc. (Alpha). In that submission, the plaintiffs alleged, among other things, that the definitive Proxy Statement filed by Massey and Alpha with the Securities and Exchange Commission (SEC) on April 29, 2011, which we call the Proxy, was false and misleading because it allegedly omitted certain facts that plaintiffs contend are material. One of the plaintiffs’ contentions centers around the work of an Advisory Committee formed by the board of directors of Massey in August 2010 to investigate, among other things, derivative claims relating to the safety of the work conditions at Massey. This committee consisted solely of the two members of Massey’s board of directors who had been appointed in August 2010. The plaintiffs allege that the Proxy failed to disclose, but should have, that the committee made an oral report to the Massey board of directors at a dinner meeting on November 21, 2010. According to the plaintiffs, the oral report by the committee indicated to the remaining board members that the committee might recommend that derivative claims be pursued against them, and that those directors might become subject to “grueling” examination by third parties the committee was considering retaining to examine Massey’s safety practices. The plaintiffs also allege that the committee recommended that Mr. Blankenship be removed, and that this was the reason he submitted his resignation on December 3, 2010. Finally, the plaintiffs allege that the foregoing led the board of directors of Massey to conclude that they had no alternative but to sell Massey to a third party.

Massey disputes the plaintiffs’ characterizations of these events. While the committee provided an oral update to the independent members of Massey’s board of directors on November 21, 2010 after the meeting of the full board of directors had been concluded, the update made no conclusions about whether or not the derivative claims should be pursued, and stated that the committee’s investigation was ongoing. Massey further believes that there is no connection between the committee’s oral update and the decision made by the board of directors to pursue a sale, or agree to a sale, of the company. While the oral update of the committee included a recommendation that at a minimum the board of directors not re-nominate Mr. Blankenship for re-election to the board of directors at the company’s next annual meeting then expected to be held in May 2011, and assess whether Mr. Blankenship as Chairman of the Board and Chief Executive Officer provided the most viable option for Massey going forward, the independent members of Massey’s board of directors did not make any decision on this matter and did not make a recommendation to the board of directors to remove Mr. Blankenship or request his resignation from his positions at Massey.

Stay tuned …