Spencer Pratt could be back in the reality show biz if he’s elected Mayor of Los Angeles … because he signed a contract to document the first family of L.A.

Sources with direct knowledge tell TMZ  … Pratt inked a deal with a Los Angeles production company to roll cameras as he runs for Mayor. The production team has been filming Spencer, his wife Heidi Montag, and kids throughout his political journey.

What’s really interesting … our sources say filming would not stop if Spencer gets sworn into office. The contract specifically provides that the show would go on.

Now we’re told Spencer and the production company have not put the cart before the horse. As of now everyone is focusing on the campaign, and they haven’t discussed details on how filming would continue if he wins. But the ink is dry in the contract.

Our sources say Heidi Montag and the kids are a big part of the show. She’s living outside L.A. with the kids in the aftermath of the fires, and Spencer is spending most of his time in L.A. running for office. If he wins, they will presumably be living in the Mayor’s mansion in the Hancock Park area of L.A.