The talk is of hundreds of thousands of people. One million. Perhaps even more.
The authorities in Pakistan are readying themselves for what could be a huge demonstration of anti-government feeling. Two separate protests, similar in their aims and ambition, are set to besiege Islamabad today - Independence Day.
One will be headed by the cricketer-turned-politician Imran Khan, of the Pakistan Tehreek-e-Insaf (PTI) party. The other demonstrators are supporters of cleric Muhammad Tahir-ul-Qadri, who runs Pakistan Awami Tehreek (PAT) and a religious organisation, Minhaj-ul-Quran.
Both groups are demanding the Government of Nawaz Sharif stand down immediately. They claim the victory Sharif and his Pakistan Muslim League-Nawaz (PML-N) won in last year's election was illegitimate, made possible only by widespread electoral corruption.
It has been 15 months since Sharif, 64, was elected to his third term as Prime Minister.
While there were some irregularities, most domestic and international observers believed the election was fair.
Khan cannot accept that. He has pressed the election authorities and the Government to investigate in a sample of constituencies to see if there was rigging.
Supporters of Qadri are equally adamant the status quo cannot continue. The cleric, who spends most of his time in Canada, has called for a "people's revolution" and has also demanded Sharif's Government stand down.
Unlike Khan, Qadri told his supporters last year to boycott the election, saying they could not hope for a fair outcome. He insists nothing has changed.
A spokesman for Qadri's PAT, said: "We are peaceful people. We are unarmed. But our morale is very high. The Sharifs should step down. Their days are numbered."
From a constitutional point of view, Sharif argues that he has right on his side and that he can take whatever steps are required to protect the capital. The protesters cite their constitutional right to demonstrate.
But as is often the case in Pakistan, the issue may be more opaque. Government officials have claimed both Qadri and Khan are supported by the powerful military and intelligence establishment, with whom Sharif has long had a difficult relationship. (He was forced out in a coup in 1999 led by General Pervez Musharraf.)
Both Khan and Qadri deny any links to the military. But others have pointed out that the military, displeased with Sharif for allowing a treason trial of Musharraf to proceed, could seek to seize on the situation.
After 68 years of independence, Pakistan faces a host of problems, including a persistent Islamist militancy, crippling power cuts and uncertainty about the regional fallout as US troops prepare to leave neighbouring Afghanistan.
Sharif certainly appears to be taking the threat seriously. Police have effectively barricaded Qadri's Lahore office and it seems unlikely he will be permitted to lead the demonstrators to Islamabad.
In his second appeal to the public in as many days, Sharif said: "We will not allow national decisions to be taken on the streets and roads. We will not permit anyone to spread anarchy."