Eighty-one-year-old Radhakrishnan, a three-time MP who represents Chirayinkil in Kerala and is a former Speaker of the state Assembly, said Chatterjee was elected Speaker unanimously and the BJP too had supported him at that time.

“To say now that he cannot vote with the BJP does not hold much water. He did not have any problem when the BJP supported his candidature to the post of Speaker,” said Radhakrishnan.

“He became a Speaker after the UPA and Left entered into an alliance. He was duly elected as a CPM candidate. He is morally bound to resign when support to the Government is withdrawn by the Left parties,” he said. “As an experienced Parliamentarian, I would humbly urge Chatterjee to vacate office. If some motion of removal is put forth, then he will have to leave office,” he said.

He said the UPA, Left and BJP had voted in favour of many issues together during the present term of the Lok Sabha. “This (Chatterjee’s stand) is childish. Every party has its own stand on issues. Even the Speaker has to toe his party’s line,” he said.

Radhakrishnan’s comments came on a day when the CPM said a “disinformation campaign” had been doing the rounds on the inclusion of the Speaker’s name in the list of MPs who withdrew support to the Government.

Politburo member Sitaram Yechury said the “Speaker’s name should be included in the CPM list as he was elected as a CPM candidate but with an asterisk denoting that currently he is the Lok Sabha Speaker, as is the normal Parliamentary practice.”

In Thiruvananthapuram, Kerala Chief Minister and CPM politburo member V S Achuthanandan said it was up to the Speaker to take a decision on his resignation. Speaking to reporters, he said the Speaker’s office should not be dragged into controversies. “The party general secretary (Prakash Karat ) has made the stand clear on the issue. It is up to the Speaker to take a decision on his resignation,” he said.

But CPM-backed independent MP Sebastian Paul also criticised Chatterjee’s stand, saying he had the political responsibility to obey the party line on the issue.