REVERE – Grim news about state aid to Revere and other cities could force Mayor Thomas Ambrosino to announce municipal employee layoffs in mid-January.”I’ll know the numbers by then,” Ambrosino said Tuesday, anticipating state budget officials will update revenue estimates by or before Jan. 15.His pessimistic forecast comes a month after Gov. Deval Patrick slashed $900 million in state spending to offset estimates the state will collect $1.1 billion less this fiscal year than it expected in July.Total revenues for the state Lottery are now projected to fall more than 4 percent below last year’s record take, likely forcing the Legislature to come up with about $40 million for Lottery assistance to cities and towns or renege on that commitment.For Ambrosino and other mayors and town officials, this drop increases the likelihood that state money vital to city and town finances will have to be cut.He announced in November that public safety jobs left vacant by retirements will not be filled. School Superintendent Paul Dakin followed Ambrosino’s lead and left several school jobs vacated by retirements empty. He has also ordered energy savings measures started in schools.State Rep. Robert DeLeo is holding out hope for the state and, by extension, cities and towns to avoid end of the year spending cuts. But he underscored worries about local aid by writing a letter to Massachusetts’ congressional district last week urging them to give the state federal aid.In an interview discussing the state’s financial health, he said: “If the revenue continues to spiral downward, I think you get to a point you can’t continue to decimate the budgets of the health and human services ? Local aid would have to be looked at, at that point.”Economists warned DeLeo and other legislators earlier this fall that Massachusetts could be in for three years of sparse budgets. Employment levels and capital gains revenues are likely to decline, the economists said, but both at unknowable rates.The prospect of prolonged spending reductions worries Dakin who has warned repeatedly that without an increase of $6.5 million next year, Revere may have to follow Lynn’s lead and close schools.