There's blood in the water at City Hall and the sharks are starting to circle Mayor Bill de Blasio. Two potential challengers to the mayor held a news conference just a few yards from where de Blasio was grilled by the press corps over the multiple investigations into his fundraising and political activities. Our Grace Rauh has the story.

Mayor de Blasio is up for re-election next year. And two top Democrats who appear to be eyeing his job seem to be having some fun at his expense.

Bronx Borough President Ruben Diaz Junior and Congressman Hakeem Jeffries teamed-up on the steps of City Hall to demand more money for a summer jobs program.

Their appearance stoked plenty of chatter about whether one or both might take on de Blasio in 2017.

"It's always flattering when people want to mention you for higher office," Diaz said.

"Well everything is always a possibility in terms of my public sector journey," Jeffries said.

They were asked directly if de Blasio has earned a second term.

"Well it's still premature," the congressman said.

Challenging de Blasio may prove tempting if the tempest around the mayor continues to grow. These days he is dogged by unflattering headlines — and pointed questions.

While stating repeatedly that everything he did was legal, the mayor is refusing to get into specifics. He ducked a question about how the owner of a rat-repellent trash bag company got a meeting with the mayor and a subsequent contract with the city after donating $100,000 dollars to the mayor's non-profit.

"Any matter under investigation I am not going to go into a play by play on," de Blasio said. "Everything was done appropriately."

The mayor insists he is not rattled by the possibility of a primary challenge next year.

"If folks want to run for this great office, bring it on," the mayor said. "We are very, very confident of the work we are doing."

De Blasio is downplaying the idea that it's getting harder to raise money for a reelection bid — but the evidence suggests otherwise.

On Thursday, the mayor will hold a fundraiser headlined by Louis C.K. The popular comedian usually sells out the house, but in this case, there are still tickets available.