Hello i have received a job offer in dubai and my employer has already started my visa procedures. Recently i got a better offer and i want to take it . I was thinking to ask my current employer to cancel my visa so as i can move to the other job . I was wondering cancelling a new work visa would have any consequences on my next work visa when is being done ? Confused about the legal impact of work visa. I have not moved to dubai yet and i do want to take the right decision . Pls advise !

Shouldn't be a problem but the first one will need to be cancelled before the second one can start. ..... also the side issue of costs incurred by the first company .... I'm not sure where you will stand on that aspect.

Thank you

since your visa isn't fully processed (you need to have a medical before your visa is issued which you have to do in the UAE) you should be fine in telling the employer you no longer want the job.
However as UKMS has pointed out you maybe liable for any costs incurred so far in processing your visa - have you actually signed an employment contract? If so, then check in there if there is a clause in regards to your visa costs.