As you are aware there is no legal obligation for an employer to allow smoking breaks.
My thoughts are that if the employer does permit smoking breaks - everyone should have breaks. There can be no compulsion to smoke - just stand outside for 'fresh' air for five minutes every hour or so.
It would be interesting to note the employer's reaction.
I used to work for a company where the 2 directors smoked. Smokers were allowed outside for smoke breaks but those of us who didnt smoke had to carry on working.