“If the claim is out of time there is no jurisdiction to consider it unless the tribunal considers that is just and equitable in the circumstances to do so. That is essentially a question of fact and judgment for the tribunal to determine … The tribunal, when considering the exercise of its discretion, has a wide ambit within which to reach a decision.” 28. In Chief Constable of Lincolnshire Police v Caston[2010] IRLR 327 , Wall LJ at para 24 said that Robertson emphasises the wide discretion which the ET has. Sedley LJ said at para 31: “There is no principle of law which dictates how generously or sparingly the power to enlarge time is to be exercised. In certain fields (the lodging of notices of appeal at the EAT is a well-known example), policy has led to a consistently sparing use of the power. That has not happened, and ought not to happen in relation to the power to enlarge the time for bringing ET proceedings.” 29. In Abertawe Bro Morgannwg University Local Health Board v Morgan[2018] ICR 1194 Leggatt LJ, with whom I agreed, said: “18. First, it is plain from the language used (‘such other period as the employment tribunal thinks just and equitable’) that Parliament has chosen to give the employment tribunal the widest possible discretion. Unlikesection 33 of the Limitation Act 1980 ,section 123(1) of the Equality Act 2010 does not specify any list of factors to which the tribunal is instructed to have regard, and it would be wrong in these circumstances to put a gloss on the words of the provision or to interpret it as if it contains such a list. Thus, although it has been suggested that it may be useful for a tribunal in exercising its discretion to consider the list of factors specified insection 33(3) of the Limitation Act 1980 (see British Coal Corpn v Keeble[1997] IRLR 336 ), the Court of Appeal has made it clear that the tribunal is not required to go through such a list, the only requirement being that it does not leave a significant factor out of account: see Southwark London Borough Council v Afolabi[2003] ICR 800 , para 33 . The position is analogous to that where a court or tribunal is exercising the similarly worded discretion to extend the time for bringing proceedings undersection 7(5) of the Human Rights Act 1998 : see Dunn v Parole Board[2009] 1 WLR 728 , paras 30–32, 43, 48 ; and Rabone v Pennine Care NHS Trust[2012] 2 AC 72 , para 75 . “19. That said, factors which are almost always relevant to consider when exercising any discretion whether to extend time are: (a) the length of, and reasons for, the delay and (b) whether the delay has prejudiced the respondent (for example, by preventing or inhibiting it from investigating the claim while matters were fresh). “20. The second point to note is that, because of the width of the discretion given to the employment tribunal to proceed in accordance with what it thinks just and equitable, there is very limited scope for challenging the tribunal’s exercise of its discretion on an appeal. It is axiomatic that an appellate court or tribunal should not substitute its own view of what is just and equitable for that of the tribunal charged with the decision. It should only disturb the tribunal’s decision if the tribunal has erred in principle—for example, by failing to have regard to a factor which is plainly relevant and significant or by giving significant weight to a factor which is plainly irrelevant—or if the tribunal’s conclusion is outside the very wide ambit within which different views may reasonably be taken about what is just and equitable: see Bexley Community Centre (trading as Leisure Link) v Robertson[2003] IRLR 434 , para 24 .”