Laurence Fox blasted his former mother-in-law in a heated on-stage rant during a recent gig.

Laurence Fox and Billie Piper

Laurence Fox and Billie Piper

The 37-year-old actor and musician - whose ex-wife Billie Piper, 33, was granted a decree nisi on the grounds of unreasonable behaviour last week - claimed during his recent concert in Manchester that he has major "beef" with her mother Mandy Kane Kent and blamed her for their shock split.

According to The Sun, Laurence introduced his song 'So Be Damned' by saying: "This is a song about my soon to be ex mother-in-law. I s**t you not. I s**t you not."

Laurence sarcastically went on: "She's a wonderful woman actually, I've got no beef with her," before he added: "Do I? Yeah I do, I've got a beef with her, man."

He later said: "It's kind of going to be a bit of a divorce-themed evening if you guys don't mind. I'm so sorry. It's just the way it turned out."

Although their divorce documents cited "unreasonable behaviour", Laurence and Billie previously released a statement clarifying that it was a "no fault" split.

Their representative said: "Billie and Laurence wish to clarify that the legal wording referred to in connection with the reported Decree Nisi is the closest option English law currently offers to a timely 'no fault' divorce."

The former couple first met in 2006 when they performed together in the stage play 'Treats' and they went on to marry in December 2007 and have two sons, Winston, seven and Eugene, four.

Their split was confirmed back in March, when the actor-and-musician announced on his Facebook page the eight-year marriage was over.

The post read: "Laurence Fox and Billie Piper have separated. No third parties are involved. For the sake of our family we request and appeal for space and privacy at this time."