Karen Gillan, Kit Harington and Lena Dunham join Andy Samberg in 7 Days in Hell

7 Days in Hell - a mockumentary HBO movie following an epic, seven-day tennis match at Wimbledon - has announced details of its staggeringly good cast.

Playing superstar tennis bad-boy Aaron Williams is Golden Globe-winning Brooklyn Nine-Nine star Andy Samberg while on the other side of the net will be Game of Thrones actor Kit Harington portraying Charles Lloyd Poole, an Andy Murray-type prodigy and certified truck driver, according to Deadline.

But that's not all. Joining the pair on set will be former Doctor Who actress Karen Gillan, Girls star Lena Dunham and Oscar-nominated Nebraska actress June Squibb.

Squibb's co-star Will Forte is also among the cast, as is Masters of Sex actor Michael Sheen, Oscar-winner Mary Steenburgen, Howie Mandel (America's Got Talent) and Fred Armisen (Saturday Night Live).

Rumour has it that Gillan will portray supermodel Lily - Charles's childhood friend who is caught between the duelling pair when she makes a sex tape with Aaron. Steenburgen is to play Charles's psychotic and controlling mother, while Forte will portray a tennis historian.

The brainchild of Samberg and Girls writer and executive producer Murray Miller (who will pen the script), 7 Days in Hell will be set in 2004 and double the length of the longest real-life match in tennis history - an eleven-hour, three-day showdown between John Isner and Nicholas Mahut in 2010.

We're predicting a Samberg/Harrington Centre Court thriller to go down in the annals of SW19 history.