The Germiston Municipal Retirement Fund, a registered pension fund, relied on rule 10.8.1 of its Fund Rules, which obliged Ekurhuleni Metropolitan Municipality as employer to top up the Fund’s returns if annual investment returns fell below 5.5%. For the 2007–2008 and 2008–2009 financial years, the Fund’s returns were below 5.5%, triggering the guarantee and resulting in a claimed shortfall of over R70 million. The Municipality refused to pay, despite earlier litigation (culminating in an SCA judgment in 2009) where the same rule had been interpreted in favour of the Fund for a previous year. In the High Court, the Municipality raised several defences: that ‘new’ evidence justified a reconsideration of the rule’s interpretation; that enforcing the guarantee conflicted with its constitutional obligations to prioritise service delivery and budgeting; that enforcement was contrary to public policy; and that the Fund owed it a duty of good faith in investment decisions. The High Court rejected these defences, upheld issue estoppel, and ordered payment. Leave to appeal was refused by the SCA, prompting the Municipality to seek leave to appeal to the Constitutional Court.