There is increasing speculation that the embattled Japanese Prime Minister, Mr Yoshiro Mori, will announce plans to resign after weeks of controversy over scandals and gaffes.
Local news media were predicting that the Prime Minister would make an announcement in the next few days.
The Tanaiste, Ms Harney, who arrives in Tokyo today to lead an Irish trade mission, is to meet Mr Mori on Wednesday.
The Taoiseach, Mr Ahern, was scheduled to meet Mr Mori yesterday but he had to cancel his visit to Japan due to the talks on the North.
Speculation on Mr Mori's future mounted as the ruling coalition yesterday announced emergency measures to bolster the ailing stock market and increase investment.
The package includes proposals to lower taxes on stock dividends and establish a special fund to absorb stock sales.
The dominant Liberal Democratic Party (LDP) said structural reforms in the economy were necessary to build a platform for growth in the 21st century.
Most analysts said they were pleased to see tax cuts mentioned as possible investment incentives.
The Nikkei hit 15-year lows this week and closed 22.66 points or 0.18 per cent down yesterday.
Pressure on Mr Mori to announce his plans to resign is mounting before a ruling party convention scheduled for Tuesday.
It is thought his resignation before upper-house elections in July would help the coalition's chances at the polls.
The political uncertainty comes at a time when the Japanese economy is slipping into recession.
One Tokyo newspaper, Nihon Keizai, said Mr Mori might make a statement on his future today. However, any announcement may be vague.
There was speculation that the Prime Minister had done a deal with the party to resign as party president but remain on as a titular prime minister.
One main purpose for the tax relief measures announced yesterday is to encourage more investment by Japanese individuals inclined to keep money in the bank despite low interest rates.
Already there is strong speculation as to who will take over from Mr Mori if he goes. The Liberal Democratic Party power-broker, Mr Hiromu Nonaka, one of those who selected Mr Mori for the job last April, is tipped.
So is Mr Junichiro Koizumi, the reformist head of Mr Mori's faction.
The former prime minister, Mr Ryutaro Hashimoto, a proponent of fiscal restructuring who resigned after the LDP lost the last upper-house election in 1998 and now a minister in Mr Mori's cabinet, is another contender.
The Trade Minister, Mr Takeo Hiranuma, and the Economics Minister, Mr Taro Aso, are also mentioned as contenders to take over the post of chief executive of the world's second-largest economy, a job which has become a poisoned chalice.
The next prime minister will join an equally lengthy list of recent leaders.
Japan has had 10 prime ministers in 13 years, with their tenures cut short by scandal, election defeat or death.
