David Miliband has announced on his blog that he will be absent from his brother Ed’s keynote speech at the annual Labour Party Conference next week.

The elder Miliband, who lives in Primrose Hill, will briefly attend the conference taking place in Liverpool from September 25-29.

But he will be at a speaking engagement in Washington when his brother addresses the party as leader.

He writes on the blog: “As is happens, I have been invited to speak at a conference in Washington on China’s rise and role in the global system, and will be there when Ed speaks on the Tuesday (September 27).”

He added that he wanted the media to concentrate on Ed’s leadership and said: “Ed is the leader and needs an open field in which to lead the party as he sees fit. I don’t want to be a distraction.

“So I am not going to be a talking head providing commentary on TV, or a media focus for soap opera during the week. It’s Ed’s show and I want it to be a success.”

The announcement is likely to further fuel speculation about a widening rift between the siblings.

In May, David and his violinist wife Louise Shackelton were at Ed’s wedding ceremony to Justine Thornton in Nottinghamshire.

But the couple were conspicuous by their absence from the post-wedding party at his brother’s Dartmouth Park home.