Shane Warne & Andrew Symonds caught on hot mics mocking Marnus Labuschagne

Rule Number 1. - The mics are always hot! 

Shane Warne and Andrew Symonds made an expletive-laden on-air chat mocking batting star Marnus Labuschagne prior to the Big Bash game last night.

Apparently unaware the cameras and mics were live, they ripped into Labuschagne for his eccentric mannerisms at the crease.

"Do something now to his ADD f***ing pills."

"Yeah, f***. Jeez it's annoying. 'No!!!' Just f***ing bat properly."

Watch the footage above.

Kayo Sports, a subsidiary of Foxtel, issued an apology on Twitter.

"Our stream started early and caught some unacceptable comments. On behalf of @kayosports and the commentary team, we unreservedly apologise," the streaming service tweeted.