Jamie Lynn Spears breaks down in tears as she admits she struggles living in shadow of Britney

Jamie Lynn Spears broke down in tears as she admitted she struggles living in the shadow of Britney.

The sisters share a tumultuous relationship and Jamie Lynn has opened up about how she's battled with self-esteem issues over the years.

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The 31-year-old opened up about the impact of being Britney's little sister on Special Forces: World's Toughest Test, shedding tears as she confided in the instructors.

"Growing up, my sister became famous, worldwide famous, when I was very young," Jamie Lynn said.

"I guess I just wanna like [prove that] I'm just like worth something. I'm so proud of her, love her to death, but I don't know. Sometimes I feel like I don't really have anything for myself."

She then added: "I struggle with self-esteem all the time."

Jamie Lynn is an actor and singer, but of course, many people know her best as the sister of Britney, who is 10 years her senior.

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The siblings have had some rocky times, and in her memoir Things I Should Have Said - published last January - Jamie Lynn described Britney's behaviour as 'erratic', 'paranoid' and 'spiralling'.

And in an interview on Good Morning America, she said: "I've always been my sister's biggest supporter.

"So when she needed help, I set up ways to do so, went out of my way to make sure she had the contacts she needed to possibly go ahead and end this conservatorship and just end this all for our family.

"It wasn't about agreeing with the conservatorship, everyone has a voice and it should be heard.

"I even spoke to her legal team, her previous legal team, and that did not end well in my favour.

"So I did take the steps to help, but how many times can I take the steps without, you know, she has to walk through the door."

Britney subsequently accused her sister of promoting the book at her expense.

The 'Toxic' singer said her younger sister 'never had to work for anything' and that she had always been 'the bigger person'.

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Writing on Twitter, the pop star said: "I looked at my phone and I see that my sister did her interview to promote her book.

"The two things that did bother me that my sister said was how my behaviour was out of control.

"She was never around me much 15 years ago at that time…so why are we even talking about that unless she wants to sell a book at my expense."

She continued: "I wrote a lot of my songs and my sister was the baby. She never had to work for anything. Everything was always given to her.

"I always was the bigger person. They all got to do it and play me and I always sat there and took it."

She added: "Hope your book does well Jamie Lynn."