Donald Trump has resigned from the film and TV union SAG-AFTRA ahead of his impeachment trial next week.

The union had been threatening to kick out the President, who left office last month, for his role in the riots in Washington DC in early January.

In his resignation letter, Trump launched a scathing attack against the union alongside a list of his achievements in TV and film, which include the TV show The Apprentice and a two-second cameo in Home Alone 2: Lost In New York.

"I write to you today regarding the so-called Disciplinary Committee hearing aimed at revoking my union membership. Who cares!" he wrote in the letter, which was published by Fox News.

"While I'm not familiar with your work, I'm very proud of my work on movies such as Home Alone 2, Zoolander and Wall Street: Money Never Sleeps; and television shows including The Fresh Prince of Bel-Air, Saturday Night Live, and of course, one of the most successful shows in television history, The Apprentice - to name just a few!

"I've also greatly helped the cable news television business (said to be a dying platform with not much time left until I got involved in politics), and created thousands of jobs at networks such as MSDNC and Fake News CNN, among many others.

"Which brings me to your blatant attempt at free media attention to distract from your dismal record as a union. Your organization has done little for its members, and nothing for me - besides collecting dues and promoting dangerous un-American policies and ideas - as evident by your massive unemployment rates and lawsuits from celebrated actors, who even recorded a video asking, 'Why isn't the union fighting for me?'"

Trump concluded: "I no longer wish to be associated with your union. As such, this letter is to inform you of my immediate resigning from SAG-AFTRA. You have done nothing for me."

In response to the letter, SAG-AFTRA issued a brief statement thanking Trump for his resignation.