Sir Paul McCartney has stepped up a bid to reclaim the ownership of the many Beatles hits he wrote with John Lennon.
The musician filed a lawsuit in New York against Sony/ATV, the publishing giant that holds the rights to classics including Love Me Do and All You Need Is Love, on Wednesday.
The original rights to the songs, penned by Lennon and McCartney between 1962 and 1971, were sold by the pair at the time in exchange for royalties.
The catalogue was then famously bought by Michael Jackson in 1985 and was sold to Sony/ATV following the star's death in 2009.
Under US copyright law Sir Paul can soon reclaim the rights to the hits.
Love Me Do will be the first song eligible to be claimed back in October 2018, with the rest of the collection's time limits elapsing at various dates ending in 2026.
Sir Paul has requested a ruling that states Sony/ATV cannot accuse him of a breach of contract or publishing agreement.
The papers state: "[The] Defendants have attempted to reserve their rights to challenge Paul McCartney's exercise of his termination rights on contractual ground.
It adds: "A judicial declaration is necessary and appropriate at this time so that Paul McCartney can rely on quiet, unclouded title to his rights."
Sony/ATV told US magazine Rolling Stone it was "disappointed" by the lawsuit and described it as "both unnecessary and premature".
The publisher said: "Sony/ATV has the highest respect for Sir Paul McCartney with whom we have enjoyed a long and mutually rewarding relationship with respect to the treasured Lennon and McCartney song catalogue.
"We have collaborated closely with both Sir Paul and the late John Lennon's Estate for decades to protect, preserve and promote the catalogue's long-term value."