Apple has launched a new legal challenge against the British government's latest attempt to create a so-called backdoor to access encrypted customer data, the Financial Times reported on Monday.

The report said Apple lodged a legal complaint last month with the Investigatory Powers Tribunal — Britain's independent judicial body — over the Interior Ministry's demand that Apple grant it access to encrypted cloud backups of data belonging to British users.

Britain dropped a previous mandate last year for such a backdoor that would have allowed access to British and US customers' data, following months of negotiations with the US President Donald Trump's administration.

However, British authorities subsequently issued a new "technical capability notice" to Apple that did not apply to US users, the FT report said.

A British government spokesperson said it would not comment on legal proceedings or operational matters, including confirming or denying the existence of individual notices.

"The UK supports strong encryption and robust privacy protections, but it is also vital that law enforcement can access communications when necessary and proportionate to protect the public from terrorism, serious crime, and child sexual abuse," the spokesperson said.

Apple confirmed the filing but declined to comment further. The company has previously said it has never built a backdoor or master key to any of its products or services and never would.

"This is a hugely important case that will have far-reaching implications for the public’s privacy rights well into the future," Ruth Ehrlich, director of external relations at human rights advocacy group Liberty, which has previously been involved in the legal case, said in a statement.

"Opening a backdoor to all of that information carries a wide range of risks to our personal data. It is critical that the government listens to the many concerns and commits to protecting our privacy rights."