PLEASANTON — The city is one step closer to ending its long-standing saga over the southeast hills after an Alameda County judge tentatively ruled in the city’s favor over a disputed 51-unit luxury housing development.

Alameda County Judge Yvonne Gonzalez Rogers issued a tentative ruling Monday denying landowners Fredric and Jennifer Lin’s suit, which claimed that a citizen referendum approved by 54 percent of voters in June 2008 was separate from the development agreement for their proposed Oak Grove development near the end of Hearst Drive.

After reviewing the written arguments, Gonzalez Rogers ruled that the referendum was filed within the required time frame and that “poison pill” language in the original approval of the development applied to it and the development agreement.

The “poison pill” provision allowed the development agreement to be invalidated if the development were overturned.