Curriculum Open-access Resources in Economics, more commonly known as CORE, was created in 2013 in response to the frustration felt by many that the Economics courses taught in Universities were unfit for purpose, failing to address key economics problems such as climate change, injustice, innovation and the future of work.
The most well-known resource is their free undergraduate level textbook, The Economy, but they have now started to offer some really interesting-looking courses too.
I made this video a while ago to show some of the features that might be useful for A-Level teachers: really good explanations, a directory of helpful resources, FT and Economist articles linked to the A-Level spec, and a tonne of other great content. There have been a few updates since, so there is bound to be more helpful context on there.