Kochi, June 3: The ruling CPI(M)-led LDF in Kerala suffered a massive political setback with the opposition Congress-UDF retaining the Thrikkakara Assembly constituency here in the much-awaited bypoll as its nominee Uma Thomas won by a historic margin of over 25,000 votes against the Left candidate Jo Joseph.

While the CPI(M), which had conducted an unprecedented grassroot level campaigning under Chief Minister Pinarayi Vijayan in the constituency, termed the defeat as "unexpected" and a "shock", the jubilant Congress said their resounding victory was a slap on the face of the second Vijayan government on its first anniversary.

Uma, the widow of prominent party leader and former legislator from the constituency late P T Thomas, showcased an impressive lead in all the 12 rounds of the counting since the beginning. While she polled a total of over 72,000 votes, her nearest rival Joseph could garner only over 47,000 votes.

BJP nominee A N Radhakrishnan came third.

The bypoll was necessitated in Thrikkakara, a complete urban constituency which comprises a major chunk of the Kochi Corporation, following the demise of Thomas late last year. Though Thrikkakara has been a Congress bastion, the bypoll captured the attention of political Kerala as the ruling CPI(M)-led front had made an unprecedented grassroot level campaign in the last one month fielding its top leaders and ministers.

Chief Minister Vijayan took the leadership of the campaign after his return from the US post treatment on May 10. Besides Vijayan, all his cabinet ministers and a majority of the MLAs and front leaders camped in the constituency for weeks and made a thorough campaign through house visits and political meetings.

Making their proposed K-Rail semi-high speed rail corridor, which is strongly opposed by the Congress-UDF, as a major campaign topic in the constituency, Vijayan had said it was a battle between the proponents of pro-development and anti-development.

Many Left leaders including CPI(M) state secretary Kodiyeri Balakrishnan had openly said the bypoll result would be a referendum on the Vijayan government. Meanwhile, the bypoll victory was a morale booster for the Congress-UDF which had suffered a huge set back in the Assembly polls held a year ago.