Indian Prime Minister Manmohan Singh has been described as "a dithering, ineffectual bureaucrat presiding over a deeply corrupt government" by a leading US daily that said his reputation was damaged by the "accusation that he looked the other way and remained silent as his cabinet colleagues filled their own pockets".

In an article "India's 'silent' prime minister becomes a tragic figure", the Washington Post said that Manmohan Singh helped set India on the path to modernity, prosperity and power, but critics say the soft-spoken 79-year-old is in "danger of going down in history as a failure".

"The architect of India's economic reforms, Singh was a major force behind his country's rapprochement with the United States and is a respected figure on the world stage.

"But the image of the scrupulously honourable, humble and intellectual technocrat has slowly given way to a completely different one: a dithering, ineffectual bureaucrat presiding over a deeply corrupt government," it said.

The daily said that for the past two weeks, everyday the Indian parliament has been adjourned as the opposition demands Singh's resignation over allegations of waste and corruption in the allocation of coal-mining concessions.

"The story of Singh's dramatic fall from grace in his second term in office and the slow but steady tarnishing of his reputation has played out in parallel with his country's decline on his watch.

"As India's economy has slowed and as its reputation for rampant corruption has reasserted itself, the idea that the country was on an inexorable road to becoming a global power has increasingly come into question," said the daily.

It went on to say that the irony is "Singh's greatest selling points - his incorruptibility and economic experience - are the mirror image of his government's greatest failings".

"Under Singh, economic reforms have stalled, growth has slowed sharply and the rupee has collapsed. But just as damaging to his reputation is the accusation that he looked the other way and remained silent as his cabinet colleagues filled their own pockets," it added.

Singh spoke last week to rebut criticism from the government auditor that the national treasury had been cheated of billions of dollars after coal-mining concessions were granted to private companies for a pittance. He denied that there was "any impropriety".

The Indian prime minister's criticism came less than two months after Britain's The Independent ran a report with the headline "Manmohan Singh - India's saviour or Sonia's poodle?"

The July 16 report observed that the Indian prime minister's reforming zeal had evaporated and slowed the country's growth.

The British daily cited observers to say he had "no genuine political power" and owed his position to Congress president Sonia Gandhi.

The story came close on the heels of Manmohan Singh being dubbed an "underachiever" by Time magazine, which asked whether the architect of 1991 economic reforms could rouse himself and put India back on the high growth path.

"Narrowing the gap between heightened expectations and the nation's capacity to deliver, should be a job for the man who launched those expectations 21 years ago with such oratorical flourish," Time said in the cover story of its Asia edition.