All you need to know about Apple Tree Yard, the new X-rated BBC series starring Emily Watson

Forget The Night Manager and Versailles – the BBC has surpassed itself with its latest licentious offering as far as their new television series goes.

Dubbed the new 'bonkbuster', Apple Tree Yard is predicted to be the most X-rated show of 2017 with a total of five whole minutes of explicit sex scenes in the first hour-long episode, which is to premiere on Sunday (22 January 2017).

The four-part thriller stars Emily Watson, 50, and Ben Chaplin, 47, and the pair are seen getting intimate in a variety of places: a cupboard, toilet and even an alleyway. Set to cause a stir, the show barely waits past the 9pm watershed as it dives straight into a raunchy scene.

An unwritten rule in the world of television shows is that they should not air adult scenes within 15 minutes of the watershed, though BBC guidelines state only that it should appear "some time after" 9pm.

The series is based on Louise Doughty's novel about scientist Yvonne Carmichael (Watson) who begins a passionate affair with a stranger who reveals very little about himself – but who plays a mysterious role in government.

Yvonne, a geneticist, gives evidence to Parliamentary select committees, and her home life is the epitome of upper middle-class suburban London affluence. Her life is full of things such as family suppers, recycling, supermarket deliveries, good wine and a happy, smooth-sailing marriage.

It all changes dramatically, however, when she is drawn into a powerfully erotic and passionate affair with the mysterious seducer – and it all begins in the House of Commons crypt. As you may have gathered, these two like doing it in public places.

And it's no wonder Yvonne is reeled in by her raven-haired lover, as Chaplin's Mark Costley is charming, handsome and wonderfully mysterious. Adapted by Amanda Coe, Doughty's erotic thriller is no doubt brought to life and explored in every way possible, and will no doubt send viewers into a frenzy when it is shown on Sunday.

Watson spoke about her role as Yvonne prior to the show's release, claiming she wouldn't go nude. She said: "The first thing I told the director was that I would not do nudity. Not because I'm a prude, but I'm vain and way too old to be naked on screen," The Sun reports. "I have known Ben for a long time and we were very honest and straightforward about it. It was fun."

Apple Tree Yard airs on BBC One at 9pm on Sunday.