Two expats donned Superman costumes yesterday to urge Cheung Kong (Holdings) to pay its ParknShop workers a higher minimum wage. Matt Pearce and his partner, who wished to remain anonymous, marched into the firm's Windsor House store in Causeway Bay and offered $50 notes to employees. While shoppers enjoyed the protest, workers kept a straight face and all declined to take the money. A saleswoman at a produce counter refused to say why she turned down the offer or how much she made an hour. 'Ask my manager for answers,' she said. Mr Pearce said the $50 notes symbolised the minimum wage per hour he and his fellow protester were urging be introduced. 'We believe $50 is a sensible level for a minimum wage for workers in ParknShop,' he said. 'Britain has a minimum wage [equivalent to] $68, while we think the people working in ParknShop earn about $25 an hour.' Mr Pearce, a private tutor who has been in Hong Kong for seven years, explained he wore a Superman costume because Cheung Kong chairman Li Ka-shing was nicknamed 'Superman Li'. 'We are using the Labour Day to protest against the big tycoons,' he said. 'We know Mr Li is a talented businessman, but I hope he'll treat his workers better because he has to be fair.' Mr Pearce was surprised he was not stopped from protesting inside the supermarket. 'I think the reason was if they had declined to let us go in, it would make them look bad in the matter of a minimum wage,' he said.