Vauxhall Meriva cutting out when slowing down

every now and then when coming to a stop the engine cuts out with the oil and battery lights coming on other times the oil and battery lights come on and the engine feels as if it has a drop in power but picks up as you accelerate away from slowing down.it happens more in the morning up to eight times and then be fine all day other days it won't happen at all in the morning and maybe once in the day,new battery on it alternator checked and good,if you can help many thanks as it has baffled me as the problem comes and goes with no pattern,i.e lights on, off etc