David Cameron arrived at the Group of Seven summit in Japan on Wednesday and added his voice to pressure on China to abide by international law in disputes in the South China Sea.

The British prime minister is suspected by the US of toning down criticism of China as he tries to make the UK the “best partner in the west” to Beijing, setting up an awkward G7 session on Asian security issues on Thursday.

But Mr Cameron made clear he backed other countries in the region in demanding that China respects a forthcoming ruling in The Hague over islands in waters disputed with the Philippines. “On the tribunal case, we believe it is in Britain’s interest to have a rule for the world that is based on adhering to the institutions and rules of that world — that suits us,” he said.