In a major jolt to the National Democratic Alliance ahead of Lok Sabha polls, Biju Janata Dal on Saturday severed its 11-year-old relationship with the Bharatiya Janata Party [Images], as the seat-sharing talks between the two parties collapsed.

"Unfortunately, the seat-sharing talks between the BJD and the BJP have failed. Therefore, we will go to the polls separately," said Orissa Chief Minister and BJD supremo Naveen Patnaik.

"The formula proposed by BJP is unacceptable to us," he said. Patnaik's announcement came minutes after a last round of talks he had with BJP's Rajya Sabha Member of Parliament Chandan Mitra, who had visited Bhubaneswar as special emissary of BJP's prime ministerial candidate L K Advani [Images].

The last-ditch effort to save the alliance failed when the BJP rejected the BJD's proposal for lesser number of seats in both Lok Sabha and assembly segments, than the previous ratio of 4:3.

Criticising BJD's severing ties with BJP, Orissa Minister of Transport Jai Narayan Mishra said BJD did not want to continue its relations with the saffron party as they had a secret agenda with the Congress. The two parties cemented the alliance in 1998, after BJD came into being a year back, in 1997.

"The BJD should get no less than 100 assembly seats in order to prevent Congress from gaining power," BJD General Secretary Damodar Rout said earlier and asked BJP not to demand 63 seats, as it was given in the 2004 election, 'realising the ground reality'.

While Patnaik had been silent on the number of seats the BJD wanted to contest, his party leaders had all along been expressing strong reservations about sticking to the old formula and favoured cut in the BJP's seat share.

The two parties had together contested the Lok Sabha elections in 1998, 1999 and 2004,  winning the majority and two assembly elections in 2000 and 2004, forming successive coalition governments for the second time.

In the last Lok Sabha elections, BJD won 12 seats and BJP seven and they had contested 12 and nine seats respcetively. The alliance together won 93 seats of the 147 seats in the Orissa assembly with the BJD winning 61 seats and the BJP winning 32 seats.

The partners had fought the last two assembly and Lok Sabha elections on 4:3 ratio. While BJD fielded its candidates in 84 seats, BJP's candidates contested in the remaining 63 seats.

A fuming BJP withdrew support to the Naveen Patnaik-led government and demanded imposition of President's rule in state.

"Since BJD supremo Naveen Patnaik ensured the end of the coalition, we are withdrawing support to his government and demand his immediate resignation," BJP Legislature Party leader and Industries Minister Biswabhusan Harichandan told reporters.

"The people of Orissa had voted for the alliance and not for Naveen Patnaik or BJD. We demand imposition of President's rule in the state," he said.

He said BJP leaders would meet Governor M C Bhandare on Sunday to formally withdraw their support to the Patnaik government.

Since the government would be reduced to a minority following withdrawal of support, President's rule should be imposed in the state, he added. The BJD had 61 members in the 147-member assembly while the saffron party has 30 Members of Legislative Assembly.