Angelina Jolie and Brad Pitt have put their plans to extend their six-strong brood on hold because of their troubled relationship, it's claimed.

According to a US tabloid report, the warring couple have abandoned any hope of adopting another child this year and called in Angelina's brother James Haven to act as mediator between them.

A source tells In Touch that during one bust up, “Poor James was trying to say, ‘Come on, that’s not fair,’ and they ended up talking right over him.”  

James is said to fear that his famous sister “may sabotage the best thing she’s ever had and walk out on Brad.”

The tension between the pair has apparently become blindingly obvious to cast and crew on the New York set of Angelina's upcoming movie Salt.

During one heated phone call, Angelina was heard telling Brad, "Will you please respect the fact that I am working right now?” and “All you have to do today is watch the kids. Will you please do it?” 

“The whole cast can tell something’s not right between them," adds another on-set insider.

With Jennifer Aniston filming The Baster a mere twelve blocks away, it's speculated that the close proximity of Brad's ex-wife is proving an added strain on their relationship.