WARSAW—An espionage trial involving a former Polish secret services agent and an ex-employee of Huawei begins in a Warsaw court on Tuesday as some European states consider whether to exclude the Chinese group’s equipment from their 5G telecom networks. Poland arrested the two men in January 2019 on suspicion of spying for China, in a move that has ramped up international debate over the potential security risks of using Huawei equipment in communications networks. Huawei has repeatedly denied its equipment can be used for espionage by authorities in Beijing, but the United States has been pressuring countries to ban it. In Europe, only Britain and Sweden have so far done so. Polish prosecutors allege that Wang Weijing, 39, using the cover of being a Huawei executive, spent more than seven years spying for China trying to bolster the company’s ability to influence the Polish government and “enable it to … …