Japanese Prime Minister Shinzo Abe announced snap December elections Tuesday in a bid to shore up support for his controversial economic policies.

Mr Abe said a planned VAT rise next year would also be delayed, a concession to critics who argue that it will hit workers' pockets hard.

"I will not raise the consumption tax to 10 per cent in October next year. It should be delayed by 18 months," he said.

But he vowed that the rise would eventually be implemented, ignoring calls from the left that it should be "categorically stopped."

Mr Abe has drawn criticism from neoliberals in Europe and the United States for including public investment in infrastructure as part of his bid to get Japan's limping economy back on track.

But the Japanese Communist Party noted that his "contradictory" approach also included "adverse reforms to social welfare and labour laws" and "tax breaks for large corporations."

General secretary Yoshiki Yamashita MP said: "Abenomics has merely widened the gap between the haves and the have-nots."

A weakening yen and consequent stronger share prices had delivered windfall profits for private companies, the party charged, but this had not been passed on to workers in the form of pay rises.

And the communists have also concentrated their fire on the PM's bid to rewrite the constitution to make it easier for Japan to go to war, as well as his commitment to nuclear energy.

Mr Abe is reputedly planning to announce a huge new stimulus focused on helping "struggling households" in his bid for re-election.

And despite a series of corruption scandals leading to the resignation of government ministers, Mr Abe retains an approval rating of around 50 per cent and is expected to win the snap election.

He has provoked fury in other Asian capitals for visits to the Yasukuni shrine honouring Japan's war dead - including 1,068 war criminals, 14 of whom are considered "class A" - and by posing in a fighter jet marked "731" in a reference to a notorious army unit that carried out gruesome experiments on Chinese prisoners of war, his fervent nationalism has played better at home.