It started as a local dispute over China's plans to build a new embassy next to the Tower of London - pitting the world's second biggest superpower against an inner-city borough that blocked the project. Two Chinese and three British officials told Reuters the Chinese government had expressed its frustration over the failure to grant planning permission for its embassy at official-level meetings. That has led officials in Britain, which is trying to forge deeper economic ties post-Brexit, to fear it could also halt their own plans to rebuild its embassy in Beijing.