Paul McCartney has had a rough trot in his mission to regain the rights to the 267-strong catalogue of mega-hits he penned for The Beatles as they’ve been handballed back and forth over the years between record labels and Michael Jackson, but his long road may soon be at an end – although not without some final hurdles.

McCartney sued in January in an effort to seek assurance that, as he believes he is entitled to under §304(c) of the U.S. Copyright Act, the rights will be his for the taking in 2018, as it allows the composers of works to terminate the transfers of rights after a certain period of time. Current rightsholders Sony/ATV responded by labeling his lapsuit “unripe”, effectively a delaying tactic.

Now, The Hollywood Reporter reports, McCartney’s lawyer Michael Jacobs has responded. “Delay would not simplify the parties’ dispute,” he wrote to the judge, “but it would prejudice McCartney. As long as Sony/ATV refuses to disavow any right to sue for breach of contract, McCartney has a cloud over the title to his works, which devalues his rights.”

McCartney is skittish about the prospects of regaining the rights following a case involving Duran Duran in which promises made in their contracts resulted in their inability to terminate, the British justice disregarding the U.S. law that states termination “may be effected notwithstanding any agreement to the contrary.”

For its part, Sony/ATV is holding its cards close to its chest, pointing out that it has so far made no challenge to McCartney’s claim, and that the Duran Duran case is still in the appeal stage, effectively telling McCartney to cool his heels until that result can inform their position.

“Here, Plaintiff is a U.K. citizen and the Grants were negotiated and entered into in the U.K. with U.K. companies with respect to songs presumably written in the U.K. in return for payment in the U.K.”

McCartney’s side disagree, claiming that “Because McCartney’s termination notices apply only to his rights arising under U.S. copyright law, the Court need not undertake a traditional conflicts of laws analysis.”

His lawyers clearly aren’t pleased with Sony/ATV’s tactics, and have responded accordingly.

“By seeking to dismiss this lawsuit, Sony/ATV intends to leave McCartney in suspense,” they claim. “Is he exposed to claims for damages if he relies on his undisputed rights under U.S. copyright law or not? Will it sue him for breach of contract or not? Can he license his copyrights as his termination notices become effective, or does that present legal risks? Will third parties be willing to negotiate with McCartney, and at what reduction in price, concerned that they may ultimately face a Sony/ATV lawsuit for interference with contractual relations?”

A lot of questions hanging over the case right now, but Sony/ATV aren’t ready just yet to give out any answers, and Sir Paul’s battle continues.