State Congress president Pradip Bhattacharya wrote to the Election Commission complaining that the Trinamool was threatening its legislators.
"The ruling Trinamool Congress party, violating the Election Code of Conduct, is threatening Congress MLAs and kidnapped some Congress MLAs," the letter alleged.
There was tension in the Left Front camp too, with three lawmakers - two of Revolutionary Socialist Party and another belonging to the all India Forward Bloc - remaining incommunicado.
A missing diary was filed at the Park Street police station as RSP lawmaker Ananta Deb Adhikari remained untraced. A television channel later claimed that Adhikari was seen in the company of a Trinamool minister and one of its top leaders. But there was no independent confirmation.
Another RSP MLA Dasrath Tirkey and an AIFB legislator Sushil Mondal was also missing till late Thursday evening.