Abhisit Vejjajiva says he has enough support to be the next PM
Thailand's opposition Democrats say they have the support of enough members of parliament to form a government.
As many as 40 MPs from the former governing party have defected to the Democrat Party and its leader, Abhisit Vejjajiva, in the last week.
The courts dissolved the governing party and banned PM Somchai Wongsawat from politics over electoral fraud.
A special session of parliament is expected to vote next week to elect a new prime minister.
The Democrat Party will propose to parliament that Abhisit Vejjajiva becomes the next prime minister.
But many of the members of the banned former governing party have formed a new party, Phuea Thai, and insist they can also form a new government.
The power struggle at the heart of Thai politics comes after a tumultuous few months in which anti-government protesters campaigned to bring down the prime minister and the whole administration.
They claimed the ruling People Power Party (PPP) was merely a proxy for ousted prime minister Thaksin Shinawatra.
They recently blockaded Bangkok's main international airport for more than a week, leaving 300,000 foreign travellers stranded and dealing a huge blow to the tourist industry.
The blockade only ended when the Constitutional Court ruled that the PPP had committed electoral fraud, and barred Prime Minister Somchai Wongsawat and other senior party members from politics.
Now the battle has moved to parliament, and the Democrats, who lost to the PPP in the last general elections in December, are seizing their chance.
One of the most powerful faction leaders in Thaksin's camp has gone over to the other side, taking as many as 40 MPs with him.
Together with some of the smaller parties that have also switched loyalties, that gives the opposition Democrats 260 seats out of the parliament's 480, says the BBC's Jonathan Head in Bangkok.
In a sign of the passions generated by the crisis, an unexploded grenade and two coffins were found outside the home of an MP, Boonjong Wongtrairat, who has defected from Phuea Thai to the Democrats, Associated Press news agency said.
The Democrats, fronted by the youthful and cosmopolitan Abhisit Vejajiva now seem poised to form a government for the first time since they were defeated in a landslide election by Mr Thaksin eight years ago, says our correspondent.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.