Copper prices were steady in London and Shanghai on Tuesday, underpinned by a firmer euro, but both markets faced pressure from nagging worries about the timing of restocking by Chinese consumers. Shanghai's most-active copper futures contract, June, rose 160 yuan to 71,230 yuan a tonne. LME copper traded at a premium of some 2,000 yuan to its Shanghai equivalent, accounting for China's 17 percent value-added tax (VAT).