Whether mere delay constitutes laches Baburin v Baburin (1990) 2 Qd R 101
Following from McLure J’s judgment in Powell v Powell  WASC 105:
 The word “laches” is used in two senses. In the first sense it means delay with acquiescence. In this context, acquiescence refers to the action of a plaintiff over a long period with full knowledge of his or her rights refraining from exercising the rights in circumstances where it can properly be inferred that they are abandoned. The conduct is sometimes described as waiver. It does not mean abstaining from interference while the violation of the person’s rights is in progress which is the province of estoppel.
 The second kind of laches is delay which causes prejudice. There is no limit on the circumstances that may constitute prejudice. However one example is where evidence is lost as a result of delay: Orr v Ford (1989) 167 CLR 316 at 330; Crago v McIntyre  1 NSWLR 729.
 The question of whether mere delay, without more, is capable of constituting laches has not been authoritively determined (see Meagher, Gummow, Lehane, “Equity Doctrines and Remedies”, Butterworths, 3rd ed, 1992, para3613 – para3616). The authors also suggest (at para3617) that where the defendant relies on that category of laches based in substance on waiver, the party against whom the defence is urged must know of the facts on which his rights depend and what his rights are (at para3617). That would appear to be correct in principle.