In an open show of power, CPM state Secretary Biman Bose said: “We will bring so many people that even Brigade ground will not be enough to accommodate them.”

The state government fell in line and issued a one-page warning that is best summed up in one sentence: “Vehicular traffic may also be diverted from any of the arterial roads and feeder roads by the traffic police on duty as and when considered necessary.”

The CPM’s Alimuddin Street headquarters has ordered its neighbouring units from South 24 Parganas and North 24 Parganas districts to bring in at least 300,000 people each for the rally, which will converge on the Brigade Parade ground at 1 pm on Sunday. Politburo members Jyoti Basu, Prakash Karat, Biman Bose and Chief Minister Buddhadeb Bhattacharjee will address the rally.

After Sunday’s rally, the closed-door session of a three-day conference will begin on Monday at Mahajati Sadan, with around 900 delegates and observers expected to attend it. CPM General Secretary Prakash Karat will inaugurate the session.

However, unlike the last party conference held in 2005 at Kamarhati, the inaugural speech will be closed to the media.

“I will not comment on whether it was right or wrong to invite the press the last time. But we have decided to restrict entry this year,” Bose said. Party sources said Sunday’s conference assumes importance given the criticism that the Left Front government has faced from a few of its allies over the land acquisition drive, the government’s handling of the minorities issue and other controversies like the ration riots.