Senators hit back at supporters of the Move Forward Party (MFP) who have launched attacks on social media against them after its leader Pita Limjaroenrat failed to get enough support in parliament to become the new prime minister on Thursday.

Of the 206 senators attending the voting on Mr Pita's prime ministerial nomination in parliament, 13 voted in his favour, 34 against and 159 abstained while another 43 senators were absent.

After the vote, Mr Pita's supporters took to social media to attack the senators who voted against him or abstained, with the hashtag "Senator's businesses'' trending on Twitter on Friday, with more than 1 million tweets.

These supporters also took aim at senators' family members and launched a campaign against businesses run by the senators.

They revealed what businesses belong to the senators, including a market, an insurance company, a beauty clinic and a football team.

A picture of a restaurant with a banner saying the senators who voted against Mr Pita or abstained were not welcome, also appeared on social media.

Writing on Facebook on Saturday, Sen Khunying Porntip Rojanasunan, who abstained, condemned the MFP's supporters who had harassed senators and their families as well as those who hold different opinions.

She said she raised the matter with the MFP's representatives who were sent to seek her support for Mr Pita. "They said they also disagreed [with the actions of the supporters], but they said they did not know how to deal with them,'' Khun­ying Porntip wrote.

Ronwarit Pariyachattrakul, another senator who abstained during the vote, wrote that unless the MFP backs down from its bid to amend Section 112 of the Criminal Code, known as the lese majeste law, Mr Pita will never get his vote for his nomination for prime minister.