Labour leader Ed Miliband wished Andrew Marr a speedy recovery as he appeared on the show which bears the broadcaster's name.
The 53-year-old journalist is recovering from a stroke and the BBC's deputy political editor James Landale filled in as host of the Andrew Marr Show.
Mr Miliband said: "On behalf of myself and everybody across politics I wish Andrew Marr a speedy recovery, all best wishes to him and his family."
At the start of the BBC1 show Mr Landale said: "It would be a much better morning if Andrew were here, not me.
"But I'm keeping the chair warm while he is away getting better. We all look forward to his speedy recovery and wish him and his family well and all the best in the meantime."
Mr Marr is the corporation's former political editor.
He began his career as a newspaper reporter, becoming the editor of The Independent before turning to television.
He has also presented a number of history programmes along with his politics show and has had five books published.