"The Central Committee decided that no member of the party should remain the Speaker of Lok Sabha after the withdrawal of support. We were asked to communicate this to him. He did not agree...we had no option (but to take action)," CPI (M) General Secretary Prakash Karat told a press conference in Hyderabad.

He said it was "unfortunate" that the party had to take the decision but added Chatterjee can appeal against it.

When pointed out that he had said that Chatterjee would take a final decision, he said, "to continue or not as the Speaker is his decision. It is up to him. But whether he will remain as our party member that we will decide."

Karat said the Central Committee was of the view that the Left parties accepted a suggestion from the ruling party in 2004 that one of its members should be the Speaker and accepted it because "we were supporting the Government".

"The Speaker cannot be from the Opposition. Between now and 2009 we will be in the opposition," he said adding it would be difficult for the Government to function properly.

But, Karat said, on July nine, the Left became part of the Opposition after withdrawal of support and the party Central Committee was of the opinion that no member of the party can remain the Speaker after that.

On expulsion, Karat said it was "unfortunate and not a happy" decision to take against the veteran leader but they were left with no option as he refused to quit the post after a party directive.

Karat said he did not want to say anything issue which will unnecessarily create controversies on the Speaker's role.

"Only thing what I am saying is as far as my party is concerned we have exercised our party disciplinary machinery or method regarding our party," the CPI (M) leader said.

He maintained that the CPI (M) ensured that during the trust motion, they did not do anything which would interfere with the role of the Speaker.

"We have subsequently taken action strictly as per our Central Committee's mandate. In our party constitution, there are methods and measures by which any party member can appeal against any disciplinary action," he said.

On the trust vote, Karat said it did not provide legitimacy to the Manmohan Singh government and the UPA has lost the "moral authority" to govern.

Noting that there is an "absence of political consensus" on the nuclear deal, "as far as the deal is concerned, the debate showed persisting sharp division on it."

On the BJP MPs' "disturbing" accusation that a Samajwadi Party leader tried to bribe them by offering Rs three crore each for abstaining from voting, Karat said that the tape submitted by a TV channel about the episode should be made public.

Karat also said there was no reason why the TV channel was not broadcasting those tapes because "it is a matter of serious public concern and interest over what actually transpired.

"Whether these charges made by three MPs are correct or are not there are prima facie grounds for proceeding in this matter. All these are major questions. So we have demanded that this tape should be immediately made public," he said.

He also said that the Left parties have met with like-minded parties and decided to launch a nationwide campaign against the Government on price rise, failure to tackle agrarian crisis and the problems faced by farmers and rural poor.