Asked directly whether he was involved in any of the briefings against colleagues revealed in Damian McBride's forthcoming memoir, Ed Miliband said it is "not my style of politics".
He said that anyone who knows him would agree that he has "never engaged in the factionalism, never engaged in the briefing".
More top news
Former Girls Aloud singer Kimberley Walsh is pregnant with her second child, she has revealed.
Chancellor George Osborne will seek to reassure financial markets on Monday morning following Britain's decision to leave the EU.
In his first outing since the referendum result, the lead Leave campaigner has outlined his vision for a post-Brexit Britain.