Britain’s Got Talent viewers have slammed Simon Cowell for being “too harsh” on 15-year-old singer Tia Connolly.

The schoolgirl from Liverpool sang a powerful version of Firework by Katy Perry, dressed in a "cool" purple outfit on tonight's (May 30) second semi-final.

In Tia’s first audition, her mum Claire surprised her by pretending she was performing herself but gave the audition up for her daughter.

On stage in front of the ITV judges, she said: “She has got me through some very hard times in my life and I feel like I owe her, so I'm giving my audition up for my daughter."

Tia explained she only usually sings in the shower before belting out I Didn’t Know My Own Strength by Whitney Houston and received four yes’s from Simon, Alesha Dixon, Amanda Holden and Bruno Tonioli. 

Viewers react to Simon Cowell's comments about Tia Connolly

After Tia performed live tonight, Simon was criticised on social media by viewers of the ITV talent show for his discouraging comments as he said she looked “cool” but would be “better surrounded by a group”.

On Twitter, one person posted: "Bit too harsh to a 15 year old #bgt"

Another said: "They legit gave better comments to that guy who farted than to poor 15yo lassie. #BGT"

This account wrote: “’I’m not saying give up…’ how encouraging #bgt”

This user said Simon’s feedback was “unduly negative”: “Seems unduly negative feedback to this very young lady from the panel. Why put them in the semifinals just to knock them down? #BGT”

A similar comment reads: “Simon didn’t really compliment her saying she’s not the best singer.”

Responding to Tia singing on the show, this person said: "Why put her through to the live shows to tell her she should be in a group ?? #BGT”

“Simon crushing the girl’s hopes and dreams live on tv #bgt #BritainsGotTalent,” posted one fan.