The intended site of the temple, in the north-Indian town of Ayodhya, resembles a war zone. This is the spot where in 1992 the destruction of an ancient mosque, the Babri Masjid, by the nationalists, sparked communal rioting which took hundreds of lives. Today the site is shrouded in barbed wire and dotted with watchtowers. The mosque ruins are patrolled by soldiers 24-hours a day.
Work began, it has been revealed, at the end of 1991, with just eight craftsmen. In 1995, with more than pounds 1m in contributions amassed, work began in earnest. Three firms of stone masons, two in Rajasthan and one in Uttar Pradesh, are pre-fabricating the decorated sandstone blocks with which the temple will be constructed.
At one of the three sites, at Karsevakpuram in Uttar Pradesh, only three miles from the disputed site, stone-cutting machines slice huge lumps of sandstone into columns, and 150 artisans chisel the forms of gods, goddesses and decorative frills and furbelows on to them.
The news of the Ayodhya temple's surreptitious construction, revealed by the Week magazine, has shocked the opposition parties and thrown the nationalist Bharatiya Janata Party-led government, so recently flush with its nuclear coup, on to its back foot.
The general-secretary of the Vishwa Hindu Parishad (VHP), one of the extremist Hindu organisations devoted to building the temple, added fuel to the fire, saying actual construction of the temple could start within two years, and would be initiated whether or not the BJP is still in power in Delhi.
"No power on earth," he said, "not even the Supreme Court, can stop the VHP from building a Ram temple at Ayodhya."
Militant statements like this have sent BJP ministers scuttling for cover. The building of the Ram temple was a central plank of the BJP's election manifesto - the home minister Lal Krishna Advani and other BJP ministers face criminal charges for their role in the mosque's demolition.
But, to fashion a "national agenda" acceptable to all its disparate coalition partners, all reference to Ayodhya was dropped from the government's programme. In response, the leading Congress politician Rajesh Pilot demanded to know whether the government was pursuing a "hidden agenda"; and, perhaps in protest at the fact that it probably is, the opposition walked out.
The site of the temple which the VHP and its allies wish to build at Ayodhya is one of the strangest and most disturbing plots of land in the country. Drawn by the controversy, and perhaps also by pious feelings towards the god Ram, aggressive Indian chauvinists are thick on the ground: it may be the only place in India where a white man feels distinctly unwanted, and implicitly under threat.
Wracked by one invasion after another over the past millennium, Ayodhya looks as if it has reconciled itself to living amidst the ruins. It is dusty, shabby, decrepit, uncared for.
Only after thorough and serious security checks is one allowed to proceed to "darshan" - "god-viewing" - at the small white tent containing an image of the god Ram, which the zealots erected following the demolition of the mosque. After a couple of seconds, one is prodded forward. The pilgrimage is over.
Ayodhya is tense because more than anywhere in India, it is where the communal energy of the Hindu nationalists has been concentrated: it is where they have chosen to stand and fight. The VHP has built Ram up into a mighty ruler, and thus the symbol of the nation.
The substance of the Hindu complaint is true: Muslim invaders did, in their own intolerant zealotry, destroy many Hindu temples, and sometimes built mosques on the same sites. Ayodhya is where the militant Hindus - by no means representative of all practitioners of the religion - plan to get their grand revenge.
The Ram temple is intended to be four times the size ofLondon's, so its building will be a correspondingly greater challenge - especially if it is done in the teeth of bitter opposition.