Van Dyke apology: Were there worse UK accents on film?
US actor Dick Van Dyke has apologised for what he called his "atrocious Cockney accent" in Mary Poppins, more than half a century after he played Bert the chimney sweep in the 1964 film.
But the peculiarities of UK accents seem notoriously hard for foreign actors to master - so who also stands out for their bad British delivery?
1. Dick Van Dyke - Bert, Mary Poppins (1964)
Van Dyke, who is from the US state of Missouri, said he had been teased for years over his Cockney accent in Mary Poppins.
The 91-year-old was recently announced as the recipient of a Bafta Britannia award for his work in TV, and said of the accolade: "I appreciate this opportunity to apologise to the members of Bafta for inflicting on them the most atrocious Cockney accent in the history of cinema."
He recently announced that he would be doing a repeat performance in song and dance for the Mary Poppins sequel, due out next year.
2. Anne Hathaway - Emma Morley, One Day (2011)
New York-native Anne Hathaway's Yorkshire accent in One Day was deemed "honkingly rubbish" by the Telegraph, although a more sympathetic Guardian reviewer wrote that it was "not as terrible as all that".
At the time, Hathaway told AP news agency about the difficulty of learning the accent: "I was so nervous about it that I can't actually watch it for myself, but a lot of people who I trust... have told me that I have nothing to worry about."
3. Russell Brand - Lonny Barnett, Rock Of Ages (2012)
Russell Brand attempted a Birmingham accent as Lonny Barnett, the sidekick of club owner Dennis Dupree, in the 2012 adaptation of the musical Rock Of Ages.
Brand, from Essex, said he adopted the Brummie brogue as a nod to Black Sabbath's Ozzy Osbourne. Commentators said Brand's performance took some getting used to, with the Metro writing it "should get him banned from Birmingham".
4. Mel Gibson - William Wallace, Braveheart (1995)
"They may take away our lives, but they'll never take our freedom!"
Braveheart gained cult status for telling the story of the 13th Century Scottish warrior William Wallace, played by Australian-American Mel Gibson. Although his Scottish accent left locals less than convinced, the film went to win five Oscars in 1996.
5. Kevin Costner - Robin Hood, Robin Hood: Prince Of Thieves (1991)
Californian Kevin Costner's attempt at an English accent as Robin Hood in Robin Hood: Prince Of Thieves has been widely mocked - not least in Mel Brooks's 1993 spoof Robin Hood: Men In Tights.
In that film, British lead actor Cary Elwes quipped: "Unlike some other Robin Hoods, I can speak with an English accent."
6. Don Cheadle - Basher Tarr, Ocean's 11, 12, and 13 (2001, 2004, 2007)
Another bad Cockney was Don Cheadle's Basher Tarr, a munitions expert who used rhyming slang.
Cheadle - like Dick van Dyke, from Missouri - later apologised for his accent in the three Ocean's films, telling an awards ceremony in LA in 2008: "Forgive me! I won't do it again!"
And when the tables are turned... Colin Firth as Gus Leroy in Main Street (2010)
He is known for his clipped English tones in the King's Speech and as Mr Darcy in Pride and Prejudice (above) - but Colin Firth's Texan accent in a US drama left some Americans confused, with his drawl deemed "laughably bad" in the US press.