It is almost certain that you are being paid this money "on account of service rendered" - logically there is a quid pro quo.
Revenue would definitely regard these payments as salary.
You can, however, write off genuine expenses of an employment against the emoluments paid by the employer. The conditions attaching to this is that the expenses must be "wholly, necessarily AND exclusively incurred in the PERFORMANCE of the duties of the employment". The emphasis is deliberate.
Common misconceptions relating to expenses include the belief that items such as travel to the place of employment qualify. They do not.If however, you are required to spend time away from your place of employment then expenses associated with travel away from base may qualify.
It's not possible to give a definitive reply without knowing the exact circumstances of you engagement.