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.