It was Sunday afternoon, the sun was shining, and Donald Trump had gathered a collection of his allies in his luxury suite to watch the Fifa Club World Cup final.

As well as entertaining members of his cabinet, including Pam Bondi, Kristi Noem and Sean Duffy, a jubilant Mr Trump had invited another important guest: Rupert Murdoch.

Just four days later, this jovial afternoon would be a distant memory.

Following the Wall Street Journal’s explosive report alleging the US president sent a lewd letter to Jeffrey Epstein for his 50th birthday, the relationship between two of the world’s most powerful men would plummet.

It is a fight that has the potential to become messy – and quickly.

In one corner of the ring stands Mr Trump, who is suing the WSJ and threatening to drag the 94-year-old Mr Murdoch into court to testify.

Should their relationship sour further, Mr Trump could, as president, unleash the Federal Communications Commission (FCC), the government regulator, on Mr Murdoch’s media empire.