CHICAGO  As workers at a window-making plant here prepared to spend a fourth night in the factory they had been told to leave for good, union leaders, bankers and company owners met into the night on Monday but the meetings ended without bringing about an end to the workers’ peaceful but increasingly tense occupation of the plant.

The layoff of 250 workers last week at Republic Windows and Doors on the North Side with only three days’ warning and without pay the workers say is owed to them had, by Monday, drawn the attention of nearly every politician with a connection to this city, numerous union and workers’ rights groups and scores of ordinary people, who arrived at the plant offering families toys, food and money.

Gov. Rod R. Blagojevich, who met with the workers Monday morning, said the State of Illinois was suspending its business with the Bank of America, Republic Windows’ lenders, and that the Illinois Department of Labor was poised to file a complaint over the plant closing if need be. Political leaders on the Chicago City Council and in Cook County threatened similar actions. Representative Luis V. Gutierrez said he was encouraging the Department of Labor and the Department of Justice to investigate. “Families are already struggling to keep afloat,” Mr. Blagojevich said.

Workers here say they blame the operators of Republic Windows and Doors, a manufacturing company that was founded in 1965, for giving them just three days’ notice before closing last Friday, with no earlier hints to the employees that orders for vinyl windows and sliding doors had fallen off.