Kate Beckinsale has thanked "warrior queen" Britney Spears for defending her against cruel trolls.

The 'Shooting Fish' star was targeted by online bullies who insisting the 50-year-old actress should post more "age appropriate content" on her Instagram page - and Britney, 42, stood up for Kate in a post on her on page - calling her "badass".

Britney wrote: "'Have you guys seen the movie 'Serendipity' with Kate Beckinsale? Well let me tell you ... if you haven't you definitely should!!!

"I adore Kate Beckinsale especially because she's from London!!! I realiaed how incredibly cruel people were talking about her IG saying she needs more age appropriate content ... she's in her fifties and I thought it was pretty badass how she responded with a mini bow in her hair looking literally 4 years old!!! ... "

Britney went on to add: "Not as bad as some of my comments saying it's sad that I'm as old as I am and I'm dancing every single day on my IG !!!

"I know what it's like to be judged so it's a ridiculous and stupid subject initially but I think it's important to HELP EACH OTHER and invite each other to places that help our souls grow !!!"

Kate was thrilled to receive the message from Britney and thanked her by writing: "Women supporting women is my favourite thing. Thank you @Britneyspears, warrior queen of all queens for your incredibly sweet post. All the love right back."

Britney's post ended with a shot back at the Osbourne family after patriarch Ozzy Osbourne admitted he was "fed up" of watching the singer's Instagram dancing videos "every day". She concluded: "I’m gonna do a photoshoot with Kate and tell the Osbourne family who is the most boring family known to mankind to kindly f*** off !! (sic)"

Ozzy previously made the comments about Britney's Instagram videos during an episode of the family's 'The Osbournes podcast', after which his son, Jack Osbourne, added: "Save Britney." Ozzy then said: "It's sad. Very, very sad," and his wife Sharon Osbourne added: "It's heart-breaking."