Doctor Who showrunner Steven Moffat has hit back at complaints from fans about the Doctor's new sonic glasses, saying "sometimes you just have to be heretical".

Fans took to social media to complain about the replacement of the Doctor's iconic sonic screwdriver with the glasses, with #bringbackthesonicscrewdriver trending on Twitter.

The new piece of wearable technology made its first appearance in The Magician's Apprentice, the opening episode of season nine. They have also made appearances in The Witches Familiar and Saturday's episode Under the Lake.

However, Moffat has defended his decision to introduce the glasses for Peter Capaldi's incarnation of the Doctor.

He told the BBC: Sometimes you have to heretical. Sometimes you actually have to embrace the heresy. Any I just thought, really, on a whim, why would The Doctor feel wedded to a screwdriver?

"Maybe he fancies varying it for a while, maybe he'll pop his sonic glasses on instead.

"It maybe resurrected the original joke which we've sort of slightly forgotten, that the screwdriver was just a screwdriver that made a noise. It's gradually become this all-purpose everything that looks really cool. It's fun to be naughty.

"I know some people are incredibly irate about it, and I'm sure the screwdriver will show up again someday. But just to show that we can – why not?"

A petition has also been launched by fan Jason Irving calling for both the sonic screwdriver and the glasses to be dropped.

His petition has already attracted over 1,300 signatures.

Irving said in the petition: "The new 'wearable technology' that the Doctor has acquired already has engraved itself into the fan's minds. Unsurprisingly, the reception of them has been pretty scathing, a sizeable chunk of fans calling them tacky and gimmicky, and quite ridiculous.

"Getting rid of the Sonic Sunglasses, if not the device altogether, forces writers to go down paths that test their abilities, prevent the format from slipping into the 'impossible situation' cliche, as the show seems to be doing just once too often."

Meanwhile, Peter Capaldi has joined Steven Moffat and Mark Gatiss by defending the BBC during an interview with Larry King.

He said: "I think the government doesn't think that the BBC supports it. [The BBC] is not answerable to shareholders and it entertains ideas - all kinds of ideas about Britain and about history and about the world and about art. I think the government don't want to pay for it.

"The BBC represents the spirit of the country. It is so important that people don't let this magnificent thing vanish. It is that dangerous."