Britney Spears gives rare glimpse of unedited vocals covering Elvis Presley in home video

Britney Spears has given fans a special birthday performance!

The popstar marked her 36th birthday by sharing a unique rendition of Elvis Presley's 'Can't Help Falling In Love' that was filmed in her sensationally festive home.

"I’ve always wanted to do a performance like this," Spears captioned the clip. "Singing in a pretty little black dress, with a simple 360, one take shot!"

"I figured since it was my birthday, why not go for it?!" she continued. "So boom... When the clock struck 12:00, I did it!!!"

The video showcased Spears' sleek fashion sense and beautifully decorated home, which included a glistening Christmas tree, tinsel-covered pillars, and hundreds of garden fairy lights.

The mother to Sean,12, and Jayden,11 (with ex husband Kevin Federline) explained that she was inspired by Madonna's  impromptu Instagram cover of her 2003 single 'Toxic' in which Madge wished Spears a happy birthday and declared: "Silence = Death!"

Fans were divided on Spears' vocals.

"I love her but it’s giving me anxiety," one person commented.

"Lovely to hear your stripped back vocals," another wrote.

Still, others weren't so kind: "Haha she sounds like a baby."

And: "Omg she sounds awful, just like a sheep."  

Spears, who has been criticised for lip syncing in the past, is almost due to wrap her long-running Piece Of Me Las Vegas residency.

And it seems she's wasted no time getting into the holiday spirit! 

Her boyfriend, 24-year-old personal trainer Sam Asghari also posted a sweet birthday clip to his Instagram, writing, "HAPPY BIRTHDAY TO MY ONE AND ONLY."

"Thank you for being you, thank you for showing me the true meaning of a beautiful woman and a strong mother, and most of all thank you for being mine," he continued. "I consider myself the luckiest man on this planet."