P.R. Laws Ap. tit. 32A, § III, Rule 21.1
2019-02-20 00:00:00+00
Upon timely application anyone shall be permitted to intervene in an action:
(a) When a statute or these rules confer an unconditional right to intervene; or
(b) when the applicant claims a right or an interest relating to the property or transaction which is the subject of the action which may as a practical matter be impaired by the final disposition of the action.