(1) The applicant must have a clear and unmistakable right, that is a right in esse;
(2) There is a material and substantial invasion of such right; and
(3) There is an urgent need for the writ to prevent irreparable injury to the applicant; and no other ordinary, speedy, and adequate remedy exists to prevent the infliction of irreparable injury.
In numerous instances and recently in Marquez v. The Presiding Judge (Hon. Ismael B. Sanchez), RTC Br. 58, Lucena City, the Supreme Court explained that the writ of preliminary injunction is issued to prevent threatened or continuous irremediable injury to some of the parties before their claims can be thoroughly studied and adjudicated. Its sole aim is to preserve the status quo until the merits of the case can be heard fully. Thus, it will be issued only upon a showing of a clear and unmistakable right that is violated. Moreover, an urgent necessity for its issuance must be shown by the applicant.

The trial court while having sound discretion on its issuance must still satisfy the strict requirements of the law. The Supreme Court has consistently held that the exercise of sound judicial discretion by the lower court in injunctive matters should not be interfered with except in cases of manifest abuse. (G.R. No. 156303; December 19, 2007)