Riga  - Latvia's four-party coalition government was teetering on the verge of collapse Monday after talks aimed at preventing industrial action by farmers broke down without agreement and serious differences between ministers became more evident.

Embattled prime minister Ivars Godmanis faces a parliamentary vote of no confidence on February 4 and the odds on him winning the ballot are shortening.

Tensions increased Monday after farmers' groups walked out of talks with Godmanis' government and said they would step up plans for demonstrations, starting with "wide-ranging action" on February 3.

Farmers, who are an important political force in Latvia, have been getting more militant by the minute. Having started their demands for increased government support with good-natured publicity stunts such as giving away free milk, arguing that it was not even worth selling, they have moved on to direct action using rolling blockades of slow- moving farm machinery.

Farmers' groups are also calling for the resignation of Agriculture Minister Martins Roze, a member of the Greens and Farmers Union (ZZS) political party.

Feeling the pressure from its core constituency, the ZZS has become less steadfast in its support for Godmanis and has threatened to withdraw its three ministers, earning a sharp rebuke from the prime minister during a radio interview on February 1.

"They should not play around with taking part in government or leaving it," Godmanis said, adding that he himself was not ready to quit.

"If the ship goes down, I will not leave it," he said.

However, if he is to survive, Godmanis will have to deal with more than just agricultural matters.

The largest party in the ruling coalition, the People's Party, has said it favours early elections or the formation of a wide-ranging government of national unity.

There is even discord within the ranks of Godmanis' own party, the awkwardly named Latvia First/Latvian Way party.

Transport Minister and joint party leader Ainars Slesers wants Latvia to spend millions of dollars attending the World Expo 2010 in China, but Godmanis disagrees.

Having only just implemented a hard-hitting austerity package that has slashed public spending dramatically as part of a 7.5-billion- euro (9.5-billion dollar) economic assistance package brokered by the International Monetary Fund, Godmanis knows that paying for a far- flung jamboree would be unpopular with voters.

Hitting back at Slesers on February 1, Godmanis criticised the minister's tendency to give well-paid government jobs to close personal contacts.

Further pressure is being exerted by President Valdis Zatlers, who has issued a March 31 deadline for a range of constitutional reforms backed by a threat to call a referendum that would dissolve parliament.

However, even if Godmanis loses the confidence motion on Wednesday, it may not mean his exit from the political stage, according to political analyst Peteris Vinkelis.

"There's a fifty-fifty chance he will survive the vote, and even if he loses there is a fairly high probability he will be nominated again as prime minister, due to coalition infighting," Vinkelis told Deutsche Presse-Agentur dpa.

"There is no strong, viable alternative in sight at this point in time. That doesn't mean one won't arise, but I don't really see anyone who wants to jump into his shoes," said Vinkelis. dpa