 Bel was President of the Socialist Group in the Senate from 2004 to 2011.Following the September 2008 Senate election, Bel was the Socialist candidate for the post of President of the Senate on 1 October 2008, but because the right held a majority of seats in the Senate, he was defeated by Gérard Larcher.In the vote, he received 134 votes against 173 votes for Larcher.