The Black Eyed Peas star has been a coach on The Voice UK since the first series on BBC One.
But following last Saturday's live show, viewers slammed the rapper for his 'disrespectful' attitude to performances, spending most of the episode on his phone.
Will was also criticised for his fast pass choice in the results show - after again taking FOREVER to make a decision - picking Jason Jones to save from the public vote.
"Will i am get off the phone and respect the contestants! You put through your worst person because u didn't know what 2 do! Poor girls!" one fan complained.
Another added: "#TheVoice is Will I am getting paid per minute of airtime he is on screen. Get on with it"
And a third wrote on Twitter: "Will's annoying antics have finally got too much for me, time to turn off The Voice. It's had its day! #TheVoiceUK #William #Extinguished"
The complaints come as ratings for The Voice 2017 on ITV continued to slide.
An average audience of 4.2 tuned in for the marathon two hour live quarter final episode last Saturday between 8:30PM and 10:30PM, the lowest Saturday rating of the series so far.
The episode - which included both the live performances and the elimination results - peaked with 5.3 million viewers.
It was down 400,000 on last weekend's previous low with numbers having dropped each weekend now since the end of the blind auditions.
The Voice UK returns this Saturday with the semi-final from 8:30PM on ITV.