Avril Lavigne has pushed back her album release because she can't work with her former husband.

The 'Girlfriend' singer – who filed for divorce from Sum-41 rocker Deryck Whibley in October last year – is reportedly struggling to finish her new album 'Pink Crust', because he is producing the record and their split is causing tensions in the studio.

A source told the Toronto Sun newspaper: “The uglier it gets in court, the uglier it gets in the studio. The first eight songs, Avril and Deryck worked with a lot of love and it came easy. But there’s three or four more to do and they just aren’t feeling it.

“It’ll be a terrific album if they can put this aside for a month or so and concentrate on what matters – the music.”

The pair are now reportedly planning a tentative production schedule in order to get the album back on track in order for it to be released within the coming months.

Avril, 25, is said to be unhappy that Deryck has demanded spousal support and under Californian law has to divide her money fairly.

The singer – who married Deryck in July 2006 – previously insisted their break-up was amicable.

She wrote on her blog: "Deryck and I have been together for six-and-a-half years. We have been friends since I was 17, started dating when I was 19, and married when I was 21. I admire Deryck and have a great amount of respect for him. Deryck and I are moving forward on a positive note."