New Delhi, April 10: The Congress high command today expelled former Kerala party president K. Muraleedharan from primary membership for six years, triggering fears of a split in the faction-ridden state unit.

Father Karunakaran, however, was spared the whip for tactical reasons.

Muraleedharan, who was suspended from the party on March 9 for indulging in anti-party activities, belongs to the party?s ?I? faction, headed by Karunakaran.

The father-son duo has been at loggerheads with the party?s central and state leaderships since their faction fielded a rebel candidate against the official party nominee for the Rajya Sabha polls in April 2003.

Soon after party general secretary Janardhan Dwivedi issued a brief statement announcing Muraleedharan?s expulsion this morning, party chief Sonia Gandhi?s political secretary, Ahmed Patel, defended the move, saying ?this was long overdue?.

?It should have been done two years ago. But we tolerated Muraleedharan?s acts of indiscipline in the name of party unity.

?He continued to issue statements against the party government in Kerala as well as against the leadership. He held anti-party conventions despite directions to the contrary and organised parallel district Congress committees,? Patel said.

Karunakaran, camping in the state, fumed at the move. ?I want to make it clear that I am not going to bow my head and meekly take this kind of decision,? he said, describing the step as a cruel and thankless reward for his services to the party for 75 years.

His faction is expected to deliberate on its next move on Tuesday. The veteran leader?s camp sees this step as a precipitate action taken at the behest of chief minister Oommen Chandy.

Fearing a split, former chief minister A.K. Antony met Sonia this morning, presumably to prevent the extreme action. But soon after the announcement of Muraleedharan?s expulsion, he said: ?I accept the high command?s decision,? though it was a sad one.

Antony, too, has fallen out with Chandy, though both were in the same group till Chandy took over from him as chief minister.

There is fear that if Karunakaran splits the party, the Congress organisation would become very weak in north Kerala. This would badly affect the Indian Union Muslim League, the second largest constituent of the ruling United Democratic Front in the state, which is strong in Malabar in north Kerala.

Indications are that a couple of smaller UDF constituents could also be drawn to Karunakaran. There are speculations about the possibility of a third front by the time the state faces next year?s Assembly elections.