The Nord Stream 1 pipeline that transports gas from Russia to Germany will undergo planned maintenance from Monday, cutting gas supplies to Europe and raising concerns about a prolonged halt to supply.
Russia has already reduced production to 40% of the pipeline's capacity, which has helped to push up European and British gas prices. Benchmark contracts are trading around 350% to 400% higher than this time last year.
Below are some of the factors explaining the impact of Russian supplies on Europe's gas markets, including those that do not rely on Russian gas directly.