David Nicholls has said that adapting novels for a television format is a “fascinating” process after rewriting his novel Us for the small screen.

His reworking of the drama will air on BBC One on Sunday.

The author and screenwriter said he always thought it would be a “tricky book to adapt as it’s told from one character’s point of view and it’s very much in his head”.

Far From The Madding Crowd World Premiere – London
David Nicholls (Matt Crossick/PA)

He added: “At the same time, there’s something about it which is very cinematic; it’s a road movie, a journey through the physical spaces of Europe but also a journey of a 20-year marriage through flashbacks.

“The novel is written through a series of very short scenes and I wanted to try and convey what it’s like to go through this journey and on screen, you can relish and enjoy.”

The writer said he worked on screenplays before becoming a novelist and therefore “had some idea of the differences between the two mediums”.

He added: “It’s very hard to adapt your own work; it’s hard to be as ruthless and clear-sighted as you need to be.

“You need to be remorseless really.

“Even a slim novel needs to be restricted when expanded on screen which was the hardest element.”

A Private War – 62nd BFI London Film Festival
(Ian West/PA)

The drama stars Tom Hollander, Saskia Reeves and Tom Taylor.

It tells the story of Hollander’s character Douglas Peterson being told by his wife that she is not sure she wants to be with him.

He then takes his family on a grand tour of Europe in a bid to patch up their relationship.

Hollander said it was “wonderful” to be able to travel to lots of different locations during filming.

He added: “It was particularly magical as we had access to the Rijksmuseum in Amsterdam, a couple of rooms in the Louvre in Paris for an afternoon, the glorious Joan Miro Foundation in Barcelona for a day and in our very own National Gallery.

“These all felt like a great privilege and it was magical because there wasn’t anyone else in them.”

He added that the series “has a particular humour to it, which is David’s writing”.

“It’s not a story without hope, it is a story about hope,” he said.

“It almost sounds a rather depressing premise but it really isn’t.”

Us begins on BBC One on Sunday at 9pm, with all four episodes being available on BBC iPlayer after it has aired.