UPDATED: Anthem wins lawsuit seeking restraining order against Cigna

In response to Cigna backing out of the merger on Tuesday, Anthem asked for a restraining order to keep Cigna from ending the deal.

On Wednesday, Anthem won a temporary restraining order that blocks Cigna Corp. from immediately terminating the $54 billion merger.

Anthem had filed the lawsuit in a Delaware court to compel Cigna to comply with the merger agreement that has been extended until April 30.

Cigna has been trying to sabotage the merger that Anthem is committed to completing either through a successful appeal or through a settlement with the new leadership at the Department of Justice, Anthem said.

[Also: Cigna sues Anthem, wants $14 billion to break up merger deal]

Cigna on Tuesday announced that in the best interest of shareholders that it was ending its planned $54 billion merger with Anthem. In its own lawsuit filed in Delaware, Cigna is asking for the $1.8 billion breakup fee plus $13 billion in damages.

Cigna does not have a right to end the merger agreement because it has failed to fulfill its obligations, resulting in the failure of the consummation of the merger, Anthem said.

"Anthem believes that there is still sufficient time and a viable path forward potentially to complete the transaction that will save millions of Americans more than $2 billion in annual medical costs and deliver significant value to shareholders," the company said.

In addition to filing this lawsuit, Anthem is pursuing an expedited appeal of the federal court's Feb. 8 decision to block the consolidation.

[Also: Anthem, Cigna merger blocked by judge; Anthem pledges to appeal]

Anthem's lawsuit is the latest step in a partnership that has turned bitter. During the trial in December, Anthem and Cigna each accused the other of breaking the terms of their merger agreement.

"Cigna's lawsuit and purported termination is the next step in Cigna's campaign to sabotage the merger and to try to deflect attention from its repeated willful breaches of the merger agreement in support of such effort," Anthem said. "Cigna's obvious efforts to sabotage the merger have been recognized by both the District Court and the national media. As the District Court noted, it could not ignore the 'elephant in the courtroom,' and the fact that Cigna was 'actively warning against' the merger and that 'Cigna officials provided compelling testimony undermining' Anthem's defense."

Twitter: @SusanJMorse