Even as the scandal has renewed public anger about rising official graft and the state of the economy, Coalgate has provided fresh ammunition for those who say India’s politicians have become so venal and feckless that they are no longer able or willing to address the country’s entrenched problems. The opposition Bharatiya Janata Party, which was already on the defensive because it had been implicated in Mr. Hegde’s investigation, has been so eager to score political points with the latest scandal that it shut down Parliament for weeks with floor protests. It refused to allow any debate — even of Coalgate — or any voting unless the prime minister resigned over the scandal. Almost an entire session was lost.

This sort of political dysfunction is hardly new in India and, in recent years, the economy was booming even as the politicians dithered. But now that the economy is slowing sharply, particularly in the ailing energy sector, analysts say India can no longer afford a government that so flagrantly fails to deliver what it promises.

On Friday, the government approved long-pending proposals allowing foreign retailers, airlines, broadcasters and other companies to enter the Indian market in an effort to shore up the faltering economy.

A decade ago, India’s leaders announced an idealistic slogan — Power for All in 2012 — and pledged to bring electricity to every corner of the country, partly by expanding coal-fired power plants. India still has more than 300 million people living without electricity, and this summer, it suffered the biggest power blackout in history. The scandal in the coal industry, meanwhile, has made it even harder for the country to generate enough electricity to meet its needs.

“Not being able to produce enough power has absolutely been the single biggest bottleneck for economic growth,” said Praveen Chakravarty, chief executive of Mumbai-based Anand Rathi Financial Services.