In 2009, the AER made a revenue determination affecting ActewAGL for the five years to 30 June 2014. ActewAGL was aggrieved that the AER had taken a rate reflecting the nominal risk-free cost of capital before the GFC. However, ActewAGL did not apply for merits review by the Australian Competition Tribunal. Instead, it tried to persuade the AER to alter its decision to reflect the Tribunals approach. The AER declined on the basis that, having made a decision, it had no power to alter it. In September 2010, ActewAGL applied for judicial review under under s 5 of the Administrative Decisions (Judicial Review) Act 1977 (Cth) in an effort to set aside the relevant parts of the Final Decision and refer the matter back to the AER for reconsideration. The ADJR Act allows just 28 days to apply for judicial review, but the Federal Court can allow an extension. The issues were: whether the Australian Energy Regulator had the power to vary a decision about the averaging period to be used to determine the nominal risk-free rate of capital after the period had been specified , and, as application had been filed well outside statutory period, whether extension of time should be granted and whether discretion should be exercised under s 10(2)(b)(ii) of the Administrative Decisions (Judicial Review) Act to refuse to grant the application. However, the Federal Court declined to review the decision because the Court was not persuaded that ActewAGL had strong prospect of success on the substantive issue and because it could not adequately explain the reasons for its delay in making the application. A judicial challenge which has implications for other people or for day to day public administration should be brought expeditiously. ActewAGL had made a considered decision not to apply for merits review in the Competition Tribunal and could not expect the same outcome as other network service providers who had taken that course.