Is it permissible for Muslim workers in farms in Spain, who are unable to leave work to perform the Friday prayer in the mosque, to gather and pray Friday in their workplace (the field), knowing that harm would result from leaving work?

If the harm that befalls Muslims by attending the Friday prayer is certain, then they are excused from attending it and should pray Dhuhr, and there is no sin upon them. If they establish a second Friday prayer in their place such that no harm befalls them, this is permissible according to some scholars, such as the Hanafis, while the majority prohibit the multiplicity of Friday prayers in a single locality without a need. So, if they act according to the opinion of the Hanafis and pray Jumu'ah, there is no harm upon them, and if they pray Dhuhr, acting according to the opinion of the majority, there is also no harm upon them.