6. Is there a ban on donations from Trade Unions to candidates?

Source: 

Article 282, Law No. 6167/2018.

(ES)

Ley 6167/2018
Art. 282. En la recaudación de fondos destinados a la campaña electoral le está absolutamente prohibido a los partidos, movimientos políticos, alianzas y concertaciones:… c) recibir aporte de sindicatos, asociaciones empresariales o entidades representativas de cualquier otro sector económico;
Estas mismas prohibiciones regirán para los candidatos y movimientos internos de las organizaciones políticas."   

(EN)

Law No. 6167/2018

Article 282. In the raising of funds destined for the electoral campaign, it is absolutely prohibited for political parties, political movements, alliances and coalitions to: … (c) receive contributions from trade unions, business associations, or representative entities of any other economic sector;
These same prohibitions shall apply to candidates and to the internal movements of political organizations.
 

The same prohibitions that apply to parties also apply to candidates