Thailand's battle against its worst floods in decades has spilled into the political arena, underscoring the deep divisions that linger more than a year after deadly civil unrest rocked the kingdom.

Efforts to prepare the capital for looming floodwaters have been plagued by contradictory messages from Prime Minister Yingluck Shinawatra's government and local authorities, both seeking to score political points, observers said.

The sense of disunity during the slow-motion catastrophe has doused hopes the crisis might bring rival political factions together following years of instability since royalist generals overthrew Yingluck's brother in 2006.

"This is no longer just an issue of natural disaster. It has become a ferocious political game," said Pavin Chachavalpongpun, a Thailand expert at the Institute for Southeast Asian Studies in Singapore.

"This competition, even during the height of the crisis, unveils a reality in Thailand: this is a deeply fragmented society in which political ideologies have overshadowed public responsibility and the urgency for national survival."

The crisis has proved a major test for the country's new leader Yingluck, who came to power just two months ago helped by the popularity of her brother -- ousted former premier Thaksin Shinawatra -- among poor Thais in rural areas.

Now it is the very people who voted for Yingluck's Puea Thai party who are suffering the most during the monsoon crisis, which has killed more than 380 people so far and affected millions in the north and the east of the country.

Conflicting statements from political enemies have rattled anxious residents, leaving many struggling to make sense of which Bangkok districts are most at risk and how best to cope with the rising waters.

"It's very confusing to know exactly who has the facts, and who really knows what to do," said Aswin Kongsiri, a Thai businessman on the board of several companies and the Stock Exchange of Thailand.

Open power struggles between Yingluck, a political novice, and Bangkok governor Sukhumbhand Paribatra from the rival Democrat Party have done little to reassure the public.

Once it became clear that the mass of water slowly pushing its way out to sea would not avoid Bangkok, the traditional heartland of the Democrats, Yingluck and the Bangkok governor quickly crossed swords.

"Listen to me and only me. I will tell you when to evacuate," Sukhumbhand told the city in mid-October.

Yingluck quickly hit back. "I want the Bangkok governor to work to his best ability and I don't want to hear this is under Bangkok authority," she said, stressing that the government's flood relief centre was in charge.

The crisis has also highlighted the strained relationship between Yingluck and the military, which traditionally supports the Democrats and has a notoriously bad relationship with Thaksin and his "Red Shirt" supporters.

Yingluck refused calls from the opposition to declare a state of emergency that would have given greater powers to army chief Prayut Chan-o-Cha.

Pro-Thaksin media have even warned of a possible "water coup" by the army, which has a long record of intervening in politics and broke up mass street protests by the Reds in early 2010, leaving more than 90 people dead.

While the generals are unlikely to use the disaster to justify a coup, the military appears to be "looking to stop the flooding without cooperating with the Yingluck government", said Paul Chambers, director of research at the Southeast Asian Institute of Global Studies at Payap University in Chiang Mai.

"Clearly the anti-Thaksin military leadership is not sympathetic to a pro-Thaksin prime minister."

While experts say the Thai floods have been exacerbated by years of environmental mismanagement and poorly controlled urban development, questions have been raised over the government's response to the floods.

"I put a lot of blame on the civil servants actually," said Aswin, the businessman, pointing out that there are "at least five or six major government agencies" in charge of dealing with water issues.

Thailand's businesswoman-turned-premier has also come under fire, with critics accusing Yingluck of indecisiveness.

As the blame game continues, Thailand's political divide looks set to linger long after the floodwaters have gone.

"This game is nasty... it will be nastier when the water recedes," said Pavin in Singapore, anticipating efforts by the establishment forces arrayed against Yingluck and Thaksin to undermine her government in the coming months.