The Hindu nationalist chief minister of India's southern state of Karnataka has resigned after just a week in office.
BS Yeddyurappa was chief minister for exactly a week
BS Yeddyurappa of the main opposition BJP quit after his coalition ally the Janata Dal (Secular) party said it would oppose him in a confidence vote.
He was sworn in last Monday as the two parties worked out a power-sharing deal after a month of wrangling.
It was the first time the BJP had been in power in southern India. Observers say state elections now look likely.
Karnataka is politically important and its capital, Bangalore, is the hub of India's booming IT industry.
Janata Dal (S) leader HD Deve Gowda said his party had decided to vote against the chief minister in the confidence vote "after the BJP refused to sign a power-sharing deal".
"The decision has been taken by the party and a unanimous resolution was passed by the party," Reuters news agency quoted him as saying.
The BJP accused the Janata Dal (S) of betrayal.
"They gave in writing to support us... but they have cheated us," Mr Yeddyurappa told reporters after submitting his resignation.
"I have full confidence that the people of Karnataka will give us a majority in the next elections."
Splits and spats
Karnataka was put under direct federal rule a month ago after the coalition government of the Janata Dal (Secular) and BJP fought over power sharing.
This is the third government in the state since assembly elections were held in 2004.
The elections threw up a split verdict with no party gaining a majority in the 224-member state assembly.
The BJP was the largest party with 79 seats, but Congress with its 64 members aligned with 58 Janata Dal (S) members to form the government.
The government lasted for 20 months before the two split.
In February 2006, the Janata Dal (S) and BJP joined hands to form a government. The two parties agreed that each would have the chief minister's post for 20 months.
The state assembly was suspended last month and federal rule imposed after the Janata Dal (S) refused to give up the chief minister's chair in favour of the BJP candidate.