China blocked an attempt by the European Union, the US and Canada to seek a World Trade Organization ruling on the legality of Beijing's tariffs on auto parts. During a regular meeting of the WTO dispute settlement body China opposed a request to set up a panel of experts to referee the trade tussle, AFP reported. The move is allowed under the rules of the 149-nation WTO, but members can only use the blocking tactic once and panels are usually created at the following dispute settlement body session. The next session is due in October, and the potential panel would have six months to issue a ruling. The three plaintiffs claim China's tariff regime puts their car manufacturers at a disadvantage to Chinese producers when they import spare parts.