Since launching a big effort to haul Japan out of deflation almost four years ago Mr Abe has forced a much more aggressive stance on monetary easing from the central bank while pushing back plans to raise sales taxes. But he has faced criticism that he achieved too little with respect to his so-called third arrow — removing structural impediments to growth in the world’s third-largest economy.

In a speech to a roomful of economists and fund managers in New York, Mr Abe said that he would focus on improving pay and conditions for the roughly 40pc of Japan’s workforce which works on a part-time or temporary basis. The pledge was light on details, but suggests that the prime minister is opening a new front in a battle to shake up the labour market.

“Next week . . . I will launch an expert group with a single mission, a mission to change the way we work,” said Mr Abe, at the event at the headquarters of Thomson Reuters in Times Square. “We must [close] the gap between regular and non-regular workers so that young people can have brighter hope for the future.”

Mr Abe has visited New York on several occasions since retaking power in December 2012, each time pledging to do whatever it takes to shake off deflation. But as consumer prices in Japan have failed to achieve lift-off — held down, in part, by the fall in the oil price and the demand-sapping effects of a tax increase in April 2014 — overseas investors have grown more sceptical.

Shinzo Abe, Japan’s prime minister, has vowed to boost the fortunes of the country’s huge army of part-time workers, as he seeks to reignite the interest of foreign investors in his signature economic reform programme

So far this year foreigners have sold a net $64bn of Japanese equities, according to Tokyo Stock Exchange data, following modest inflows of $23bn and $4bn in 2014 and 2015, respectively. In 2013, with excitement over ‘Abenomics’ at its peak, inflows came to $155bn.

Mr Abe’s speech came hours after Japan’s central bank had tweaked its three year-old monetary easing programme by setting a cap on 10-year government bond yields and promising to deliberately overshoot its 2pc inflation target. Japan’s consumer price index stood at minus 0.5pc in July, excluding fresh food.

Some observers said that the moves showed that the BoJ was running out of room for further stimulus, having already committed to buying up huge amount of bonds and stocks to stir up economic activity. “Investors have started to doubt the sustainability and scalability of the central bank’s monetary framework,” said Fred Neumann, co-head of Asian economic research at HSBC in Hong Kong. “Nothing unveiled today will remove those doubts.”

Mr Abe’s speech yesterday was prefaced by videotaped remarks from Robby Feldman, chief economist at Morgan Stanley MUFG Securities in Tokyo, who said that reforming Japan’s notoriously rigid labour market should be the top priority for the prime minister. “Abenomics is fighting against history,” he said. “The problem is that this is a journey of a thousand miles and we’ve only taken a couple of steps so far.”

Also at the event was Dan Loeb of Third Point, an activist investor who

has taken big positions in Japanese companies including Sony, IHI and Fanuc. Mr Loeb said that the BoJ had “set the right conditions” for growth but it was time for politicians to do their part.

“It’s true in Japan and it’s true around the world; we’ve relied too much on monetary policy,” he said.

“We’ve got to take the crack-cocaine pipe away and focus on real fiscal policy and structural reform to get growth going again.”

Published in Dawn, Business & Finance weekly, September 26th, 2016