Chris Chibnall has had second thoughts about ending 'Broadchurch'.

Olivia Colman and David Tennant in Broadchurch

Olivia Colman and David Tennant in Broadchurch

The third and final series of the popular crime drama will hit television screens on Monday (27.02.17) and, although he's looking forward to spreading his wings and jumping across to 'Doctor Who' later this year, he keeps questioning why he's walking away from the show's main stars Olivia Colman and David Tennant.

Speaking to the Radio Times, he said: "Once I step away from the computer, I hope I've given everything to it -- like a footballer leaving everything on the pitch. The emotion goes into the show. Any success is not in our hands, it's in the hands of the audience -- they decide what they want to talk about. It's very emotional. It's hard to say goodbye. I've asked myself, 'Why am I walking away from the two best actors in the country?'"

But the 47-year-old writer had already decided that the show would only last three series when he signed on to the project but he wanted to make sure that it involved multiple storylines and be jam packed with shocking twists and lots of surprises.

He explained his planning process: "I have four giant whiteboards and a brilliant script editor. We storyline everything and then start with the characters... When you plot an hour-long episode, you have to do it very tightly in four acts around the ad breaks."

And Chibnall will no doubt take the same approach when he starts to pen 'Doctor Who'.

He said: "We'll cast the role in the traditional way: write the script, then go and find the best person for that part in that script. You couldn't go out and cast an abstract idea."

The talented writer will take over from current show runner Steven Moffatt at the beginning of 2018 once Peter Capaldi - who has played the Doctor since 2013 - makes his final appearance as the time-travelling scientist in the Christmas special.

He explained: "The creative possibilities are endless, but I have a very clear sense of what we're going to do, without even knowing who's going to play the part."