 They were selected by the Prime Minister of the day, but were formally appointed by the Sovereign.A Lord of Appeal in Ordinary had to retire at the age of 70, or, if his or her term was extended by the government, at the age of 75; after reaching such an age, the Law Lord could not hear any further cases in the House of Lords.The number of Lords of Appeal in Ordinary (excluding those who were no longer able to hear cases because of age restrictions) was limited to twelve, but could be changed by statutory instrument.