PARIS (AP) — The Socialist candidate for the French presidency is seeking to breathe new life into his flagging campaign.

Benoit Hamon held a boisterous rally Sunday that packed out an indoor sports and concert arena in Paris with at least 20,000 people.

Since he won the Socialist primary in January, the 49-year-old former minister has struggled to carve out a space for himself in the campaign and failed to unite the party behind him.

Hamon and far-left candidate Jean-Luc Melenchon both have a big obstacle blocking their route to the presidential Elysee Palace: each other.

Both are hunting on shared ground on the left for votes, but neither is willing to make way for the other.

Melenchon rallied tens of thousands of people in Paris on Saturday.