The US government has put a final block on the prospect of oil exploration in the country’s Arctic in the foreseeable future, cancelling plans to sell more drilling leases in the region, and refusing to extend leases previously sold to Royal Dutch Shell and Statoil. The decision was welcomed as a victory by environmental campaigners, and attacked by the industry and politicians in Alaska as a blow to US energy security. The possibility that any oil companies would want to explore in the Arctic seas off the north coast of Alaska was already remote following Shell’s announcement that it was ending its drilling campaign in the region having found only traces of oil with its first well this summer. The decisions by President Barack Obama’s administration set the seal on that position, and could block further development in the Arctic for decades. Lisa Murkowski, a Republican senator for Alaska, described the administration’s move as “stunning”, saying it betrayed the interests of US energy security.