Friends and foes alike are seeing the upset defeat in the Sakon Nakhon by-election of the Bhum Jai Thai Party as having brought down a notch the flamboyant faction leader Newin Chidchob.

A coalition partner, who spoke on condition of anonymity, said Newin would have acted like an out of control achiever gloating over the coalition alliance, if his electoral candidate had won the by-election on Sunday.

Even Newin's Bhum Jai Thai colleagues like Somsak Thepsuthin conceded Newin needed to be reined in to ensure the consolidation of the coalition, the partner said.

Democrats appeared to heave a sigh of relief at the by-election defeat, for it allows the main coalition party to gain a firmer grip on Newin.

A source from Pheu Thai Party said Phuea Paendin's key member Pinij Jarusombat had sent his canvasser to help Pheu Thai's candidate in order to block Newin's party.

Prime Minister Abhisit Vejjajiva said his coalition partners from Bhum Jai Thai should reflect on the voting outcome.

"I think the defeat is a lesson reminding the coalition to work harder," he said.

Abhisit said he saw no shortcut way to secure election victory. Time and effort must not be spared in building a support base, he said.

He attributed the Pheu Thai victory to the votes cast in the stronghold of the main opposition party, rather than the popularity of ex-premier Thaksin Shinawatra, as speculated.

He said the by-election outcome was not a litmus test for the next general election. The by-elections in the past five to six months had varying results which appeared to have no bearing on the political situation on a nationwide scale.

He said also he did not see the by-election votes as a gauge of ex-premier Thaksin Shinawatra's popularity.

Pheu Thai Party MP Jumphot Boonyai from Sakon Nakhon said he was still committed to his decision to switch his banner to Bhum Jai Thai, even though the party lost the vote on Sunday.

He said he did not base his decision on the by-election outcome but on where he could better perform his job.

He conceded, however, that a number of incumbent Pheu Thai MPs might cancel their defection plans after the Bhum Jai Thai defeat.

Pheu Thai MP Somchai Phaetprasert said his main opposition party will not sit on its laurels over the by-election victory, but move on to planning for the general election.

He said he was trying to expand his party's strongholds to cover the lower Northeast in Buriram, Surin and Nakhon Ratchasima. Buriram and Surin is known as the backyard of the Newin faction and Nakhon Ratchasima is the bastion of Ruam Jai Thai Chart Pattana Party.