The United Thai Nation (UTN) Party has called on its supporters not to feel disappointed by party leader Pirapan Salirathavibhaga's decision to resign as a list MP to concentrate on his duty as the prime minister's secretary-general.
UTN secretary-general Akanat Promphan said on Twitter on Saturday that Mr Pirapan chose to relinquish the MP post so he could serve Prime Minister Prayut Chan-o-cha, whom he holds in high esteem.
The UTN leader's decision to step down as MP came after Deputy Prime Minister Wissanu Krea-ngam, also a legal expert, said Mr Pirapan won't need to quit as the PM's secretary-general until the swearing-in of MPs.
Gen Prayut is adviser to the UTN.
Although the law forbids an MP from concurrently holding public office, an MP's status is not made official until the swearing-in process is complete, according to Mr Wissanu.
Mr Akanat on Saturday said he believed Mr Pirapan had considered well his resignation as MP before formally making the announcement.
The person moving up the list to take Mr Pirapan's place is Anucha Burapachaisri, the government spokesman.
Mr Pirapan will retain the PM's secretary-general post until Gen Prayut's successor as PM is sworn in, a process that could take several weeks.
Although parliament's election of a new prime minister is expected to take place on July 13, formalising the premiership and the appointment of a new cabinet will take time.
On Friday, Mr Pirapan, also a UTN prime ministerial candidate, posted a message on social media pledging to serve Gen Prayut until the rest of his time as prime minister is up.