“42. For the purposes of the principle in Inco Europe, it is only if the legislative instrument has a clear, objectively assessed meaning, having regard to all the circumstances and all indicators of the legislators intention available to the person subject to the law (assisted as necessary by his legal advisers), and that meaning is contrary to the literal meaning of the text of the instrument, that it will be appropriate for the Court to give a rectifying interpretation to the instrument. Given the primacy ordinarily to be given to the language used in a legislative instrument as an indicator of the legislators intention, the countervailing objective indicators that, despite the language used, the legislators intention was different need to be very strong, as Lord Nicholls emphasised in Inco Europe. It must be clear that the true intention of the legislator, objectively assessed, was different from the language used by the draughtsman. It is only if the Court has no doubt that the draughtsman “slipped up”… i.e. that there was a mistake made in the language chosen by the draughtsman to give effect to the intention of the legislator, that it can be confident that the proper interpretation of the provision is given by other objective indicators of the legislators intention. This is an approach to interpretation of a kind which is not unique to legislative instruments, but is of general application in the construction of all sorts of instruments which are intended to have legal effects: compare, e.g. Mannai Investment Co Ltd v Eagle Star Life Assurance Co Ltd[1997] AC 749 , esp. at 797G per Lord Steyn. 43. Although in this judgement I have used the expression “rectifying interpretation” as a convenient shorthand expression for the process of construction pursuant to the guidance in Inco Europe, I should make clear that properly speaking the court does not rectify or amend the legislative instrument. It gives it its true meaning, arrived at by the process of objective interpretation described in the authorities referred to above .… 45. In deciding whether it is appropriate to identify the true meaning of a legislative instrument as supplemented by implication or by substitution of formulation in this way, it will be necessary to have regard to other relevant guides to interpretation which may apply. Of these, an important guide will be the principle that the language used in penal legislation is to be strictly construed, to which Lord Nicholls called attention in Inco Europe at P. 592 H, in the passage quoted. 46. Again, this is not an approach which is unique to the Inco Europe type of situation. It is a general approach to interpretation of legislation, to be born particularly in mind when it is sought to argue for a construction by reference to aids to interpretation external the text of the legislation itself.… 47. The principal penal legislation is to be construed strictly is a long-standing one, of recognised constitutional importance… The rationale for this principle is that it is presumed within our constitutional system that the legislator intends that a person subject to a penal regime should have been given fair warning of the risks he might face of being made subject to a penalty. 48. But it is not an absolute principle. The overarching requirement is that a court should give effect to the intention of the legislator, as objectively determined having regard to all relevant indicators and aids to construction. The principle of strict interpretation of penal legislation is one among many indicators of the meaning to be given to a legislative provision. It is capable of being outweighed by other objective indications of legislative intention albeit it is itself an indicator of great weight. As Bennion says, at p.750, “In accordance with the basic rule of statutory interpretation a penal enactment will not be given a strict construction if other interpretive factors weigh more heavily in the scales”;… If other objective indicators of legislative meaning and intent are sufficiently clear, and it is obvious to the requisite degree that the draughtsman has made a slip in the language he has used, a person subject to a penal regime may be taken to have been given fair warning even though the interpretation adopted by the court involves some implication of terms in, or substitution for, the text of a relevant legislative provision.”