Sarah Parish’s new crime drama Bancroft has come under fire from viewers who claimed the first episode was plagued by mumbling and poor sound quality.

Many said they could not fully enjoy the action in the ITV thriller because they could not hear the dialogue well enough.

“Is it me or is the sound really quiet and muffled?” asked one person on Twitter.

“I was excited to get stuck into #Bancroft tonight but the sound quality is appalling making it difficult viewing!” said another disgruntled viewer.

“#Bancroft Another promising drama marred by dodgy sound balance – Det Andy is especially mumbletastic. And that scene with loud background music, shower sound, TV news…” griped another.

One moaned: “Lasted half an hour of #Bancroft nah too much mumbling too boring.”

Some people said they got around any sound issues by switching on the subtitles.

“Why can’t people talk CLEARLY in programmes?! #Bancroft It’s bad enough I have hearing loss but I shouldn’t have to ask people I visit to put their subtitles on so I can understand their mumblings,” said one viewer.

Another said: “Finding the sound awful on #Bancroft! Pitying my neighbours so had to put the subtitles on! Not good enough @ITV.”

Several British television dramas have been hit by complaints over mumbling, with Happy Valley, SS-GB and Jamaica Inn all being criticised.

The four-part ITV drama, written and created by Kate Brooke, sees detective Elizabeth Bancroft (Parish) try to bring down the pernicious and vicious Kamara gang.

The drama really unfolds though when her colleague – ambitious recruit DS Katherine Stevens – starts working on the case of a woman called Laura, who was killed 27 years ago.

There was a positive response to Bancroft from many who did appear to hear it clearly.

And many people praised Parish’s acting skills.

One pleased viewer said: “@DrSarahParish you were utterly compelling and brilliant as always hon ! Love lily am hooked.”

Another wrote: “@drsarahparish is just amazing in #bancroft, really enjoyed the first episode can’t wait for the second.”

Bancroft continues on ITV on Tuesday.