Mr Nat, an MP for Bangkok, said Pheu Thai members were accusing City Hall of not dredging the canals because they wanted to discredit Bangkok Governor Sukhumbhand Paribatra, who is also a Democrat member.
"The government is also responsible for some of the canals, such as the ones in Lat Phrao and Makkasan," the opposition MP said.
He called on members of the Pheu Thai Party and the government to stop politicising the flood issue and to seriously get down to solving the problem.
Chartthaipattana Party chief adviser Banharn Silpa-acha said Bangkok will definitely not experience a repeat of last year's great flood.
The former prime minister said the recent flooding in Bangkok was caused by heavy rain which overwhelmed the city's drainage system.
"I guarantee that there will be no big flood (this year) and there's no need for the brothers and sisters of Bangkok to be worried," Mr Banharn said. "There might be small floods during heavy rain, but it should return to normal within a couple of days."
He said the government will be able to deal with the water situation this year.
In Sa Kaeo, the floodwater level in Aranyaprathet district has started to drop, but rescue workers are still having difficulty reaching flood victims in some areas.
The main roads in Aranyaprathet remained heavily flooded and people can travel only by boats or in military trucks.
The flood water in the district was measured at about one metre deep on Friday morning and was starting to fall. There were no reports of another mass of water entering the eastern border province, which is a major entry point to Cambodia.
Soldiers, physicians, nurses and volunteers continue trying to distribute food and drinking water to people stranded in hard-to-reach areas.
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Sa Kaeo hit by flooding. (Photos by Somchai Poomlard)
In Ang Thong, on the Central plain, the flood water level was measured at 30 centimetres on Friday following heavy rain overnight.
Many roads in the central province were inundated, causing problems for travellers.
Ang Thong mayor Chai Suwaphan said three large pumps were brought in to help drain out water in the municipality.
Mr Chai said the situation should return to normal late today if there is no more rain.