Brazil's Supreme Court has upheld a ban on social media platform X, formerly known as Twitter.

The judges voted unanimously in favour of the measure, meaning the ban will stay in place.

X has been suspended in Brazil since the early hours of Saturday after it failed to appoint a new legal representative in the country before a court-imposed deadline.

It is the latest development in a feud between Supreme Court Justice Alexandre de Moraes and X's owner Elon Musk which began in April, when the judge ordered the suspension of dozens of accounts for allegedly spreading disinformation.

Justice Moraes had called for the five-member panel to rule on the suspension, which has caused division in Brazil.

One of the justices, Flávio Dino, argued that "freedom of expression is closely linked to a duty of responsibility".

"The first can't exist without the second, and vice-versa," he added.

Reacting to the decision to ban X, Mr Musk had earlier said: "Free speech is the bedrock of democracy and an unelected pseudo-judge in Brazil is destroying it for political purposes."

In his ruling, Justice Moraes gave companies, including Apple and Google, a five-day deadline to remove X from its app stores and block its use on iOS and Android devices.

He added that individuals or businesses that are found to still be accessing X by using virtual private networks (VPNs) could be fined R$50,000 ($8,910; £6,780).

X closed its office in Brazil last month, saying its representative had been threatened with arrest if she did not comply with orders it described as "censorship", which it said was illegal under Brazilian law.

Justice Moraes had ordered that X accounts accused of spreading disinformation - many of which belonged to supporters of the former right-wing president Jair Bolsonaro - must be blocked while they are under investigation.

Brazil is said to be one of the largest markets for Mr Musk's social media network.

With access to X blocked, many Brazilians have been turning to microblogging platform Bluesky as an alternative.

Bluesky announced on Saturday that it had registered half a million new users in the South American country over the two previous days alone.

Among those pointing followers to his Bluesky account was Brazil's president, Luiz Inácio Lula da Silva, who on Thursday tweeted links to his social media accounts on platforms other than X.

Lula's Bluesky profile was top of the list, which also included links to his Instagram, WhatsApp, Threads, TikTok and Facebook accounts.

Bluesky CEO Jay Graber expressed her delight at the influx of new users, posting in Portuguese and English: "Good job Brazil, you made the right choice."