Across China, homebuyers are refusing to pay mortgages as property developers drag on construction projects, escalating the country’s real estate crisis and risks of bad debt for banks.

Buyers of 35 projects across 22 cities have decided to stop paying mortgages as of July 12 due to project delays and a drop in real estate prices, Citigroup Inc. analysts led by Griffin Chan wrote in a research report distributed on Wednesday.

The payment refusals underscore how the storm engulfing China’s property sector is now affecting the country’s middle class, posing a threat to social stability. Chinese banks already grappling with challenges from liquidity stress among developers now also have to brace for homebuyer defaults.