Japanese voters have given their prime minister and his ambitious economic reform plan a boost as Shinzo Abe’s Liberal Democratic party won a majority in Japan’s upper house elections.

After two decades of lacklustre growth, “Abenomics” – Mr Abe’s plan to jolt Japan’s economy back to life – continues to shake things up. Trillions of yen in fiscal stimulus and the Bank of Japan’s commitment to double the monetary base have paid dividends. Consumer confidence, despite a dip last month, remains close to a six-year high. The Nikkei 225 share average is up more than 60 per cent over the past eight months.

Can the success last? Mr Abe’s strong position suggests it can. His LDP-led coalition already held a supermajority in Japan’s lower house of parliament and now has a working majority in the upper house, giving the prime minister firm control of the legislative agenda. Short of a crisis, Mr Abe need not face elections before 2016. Such time to press forward with reform is a priceless asset in a country that has seen 15 prime ministers in 20 years.