Ukip leader Henry Bolton is under pressure to resign as party leader after graphic messages have reportedly emerged in which Jo Marney had joked with a friend about child sex abuse.
Earlier, his 25-year-old glamour model girlfriend was suspended for racist remarks about Meghan Markle leading Paul Oakden, Ukip's chairman, to say that Bolton must choose between keeping his role as party leader or staying together with his new girlfriend.
But the Telegraph reported that in comments too graphic to print, Marney had sent Facebook messages "to make the case for the gravity of animal abuse by comparing it to acts of child abuse".
She said her friend had edited the message "make it look like I was saying random weird things".
"I was highlighting the point of animal abuse by using a baby in comparison to the animal," she said, according to the Telegraph.
Ukip refused to comment but a friend of Marney's claimed they were taken out of context and had been "part of an outrage competition".
Ukip MEP Bill Etheridge has urged Bolton to quit ahead of a planned vote of confidence due to be held by the party's national executive committee next Sunday (21 January).
In a video posted to Facebook, Etheridge said: "It appears that we are now seeing Ukip resources, which are at best scant, being used to defend Henry's private life". The MEP threatened to step down as Ukip's shadow sports minister if Bolton "insists on prolonging this agony".
If Bolton quits before the committee meeting, Ukip will be forced to elect its fourth leader in less than two years.
The controversy erupted after a series of racist messages in which Marney referred to black people as "ugly" and said Markle's genes would "taint our royal family".
Marney has apologised "unreservedly" for the "shocking language" in the messages, but claimed they were "taken out of context".
"I'm absolutely devastated by the messages that I've sent and the distress that I've cause anyone by those messages. They were unnecessary, they were reckless, they were overly exaggerate purely for effect," she said.
Bolton, who left his wife Tatiana before his relationship with Marney became public in early January, was elected Ukip leader last September.