New drama: Pets, Pete and Amy Winemouse

Doherty and Winehouse use baby mice to get her video message across to Blake Fielder-Civil's prison cell

On the face of it, it's hard to guess what might link a litter of baby mice; the singer Amy Winehouse and millions of YouTube viewers. Yet the three elements have come together in a web video of the singer playing with a box of baby mice, alongside Babyshambles singer Pete Doherty.

The film shows Ms Winehouse holding up one of the rodents and using it to plead with her jailed husband, Blake Fielder-Civil, not to divorce her.

This latest disturbing display will almost certainly add to the antipathy between Winehouse's family and that of Mr Fielder-Civil. The constant revelations about the couple are thought to have fuelled anger between Winehouse's mother and her mother-in-law over who is to blame for their problems.

Janis Winehouse lays the blame for her daughter's use of hard drugs squarely at the door of her son-in-law. In a bitter outburst, she accused Mr Fielder-Civil of being a scheming freeloader who manipulates the press with a view to a multimillion-pound divorce settlement.

Mrs Winehouse, who is divorced from Amy's father Mitch, said: "As far as I'm concerned, Blake more than played his part in Amy's downfall. People I trust have told me Amy didn't start on the hard drugs until she met Blake – and I think that says it all. Don't get me wrong: I know she dabbled in drugs before. But she was always adamant that she would never touch the hard stuff.

"That all changed when she met Blake. She didn't start self-harming until Blake came along either. I know Georgette, Blake's mother, says the opposite and blames Amy for Blake's downfall, but that's absolute rubbish. I think she's fighting a good cause for her son so he gets a good payout from any divorce."

But Mr Fielder-Civil's mother Georgette, a Nottinghamshire hairdresser, says her son is being "conveniently" blamed for the singer's problems. "Janis has never said a nice thing about Blake. It's been too convenient for her to blame him for Amy's addiction. Although we are not in touch, I believe Mitch is as scared as we are about what the hell will happen to them when Blake gets out."

In the internet video the singer picks up a rodent and, in a mouse "voice", sends a message to her husband, on remand in prison accused of assault and perverting the course of justice. Doherty joins in, picking up another and saying: "If you divorce her, you'll have me to deal with."

The RSPCA said baby mice should always be left undisturbed, as "strange human smells" could lead their mothers to kill them.