 Prerogative powers were formerly exercised by the monarch acting on his or her own initiative . Since the 19th century , by convention , the advice of the prime minister or the cabinet — who are then <unk> to Parliament for the decision — has been required in order for the prerogative to be exercised . The monarch remains <unk> empowered to exercise the royal prerogative against the advice of the prime minister or the cabinet , but in practice would only do so in <unk> or where existing precedent does not adequately apply to the circumstances in question . 
