Disunity killed former Labor govt: Shorten

Disunity within Labor was the former government's greatest mistake, says Bill Shorten.

Opposition Leader Bill Shorten says Labor's greatest mistake in government was disunity.

"One of the greatest mistakes was disunity in the government ... (but) I've been very fortunate to have quite a marvellous run of unity within the Labor party," Mr Shorten told reporters in Canberra on Wednesday.

Mr Shorten was responding to a new ABC TV series, The Killing Season, in which Julia Gillard accuses Kevin Rudd of bullying and frontbench members discuss the Labor leadership turmoil.