To prevail on a claim for tortious interference with prospective business relations, the plaintiff must establish: (1) there was a reasonable probability that the plaintiff would have entered into a business relationship with a third party; (2) the defendant either acted with a conscious desire to prevent the relationship from occurring or knew the interference was certain or substantially certain to occur as a result of the conduct; (3) the defendant's conduct was independently tortious or unlawful; (4) the interference proximately caused the plaintiff injury; and (5) the plaintiff suffered actual damage or loss as a result. Coinmach Corp. v. Aspenwood Apt. Corp., 417 S.W.3d 909, 923 (Tex. 2013).  A plaintiff does need to prove that the contract would have certainly been made but-for the alleged interference. But, there must be evidence that it was reasonably probable that the prospective contract or business relationship would have resulted but-for the alleged interference, considering all of the facts and circumstances surrounding that transaction. Richardson-Eagle, Inc. v. William M. Mercer, Inc., 213 S.W.3d 469, 475-76 (Tex. App.—Houston [1st Dist.] 2006, pet. denied).   Moreover, there must be a showing that more than mere negotiations occurred. Id. at 475.  Further, if plaintiff succeeds in establishing causation, the plaintiff must show with reasonable certainty the amount of harm caused as there can be no recovery for damages that are speculative or conjectural.  Hill v. Anderson, 420 F. App'x 427, 431-32 (5th Cir. 2011).  One of the more difficult elements of this claim is the requirement that the defendant’s conduct be independently tortious or unlawful.  Conduct which is merely "sharp" or perceived as "unfair competition" is not actionable as tortious interference with prospective business relations.   Wal-Mart Stores, Inc. v. Sturges, 52 S.W.3d 711, 713, 726 (Tex. 2001).  The plaintiff is not required to prove the independent tort, only establish that the defendant's conduct would be actionable under a recognized tort.  Id.  Trespass is an independent tort that can support a claim for tortious interference with prospective business relations.  Coinmach, at 924.   Defamation would be another possible independent tort that could be used with this claim.  

Defenses.  Justification is an affirmative defense to tortious interference with contract and tortious interference with prospective business relations.  The Prudential Ins. Co. of America v. Financial Review Serv., Inc., 29 S.W.3d 74, 78 (Tex. 2000).   The justification defense can be based on the exercise of either one's own legal rights or a good-faith claim to a colorable legal right, even though that claim ultimately proves to be mistaken.  Id. at 80 (citing Texas Beef Cattle Co. v. Green, 921 S.W.2d 203, 211 (Tex. 1996)).   If a trial court finds as a matter of law that the defendant had a legal right to interfere with a contract, the defendant has conclusively established the justification defense, and the motive is irrelevant. Id.  Alternatively, if the defendant cannot prove justification as a matter of law, it can still establish the defense if the trial court determines that the defendant interfered while exercising a colorable right, and the jury finds that, although mistaken, the defendant exercised that colorable right in good faith. Id. 

Statute of Limitations.   A tortious interference claim is governed by the two year statute of limitations. See First Nat'l Bank of Eagle Pass v. Levine, 721 S.W.2d 287, 289 (Tex.1986).