
Suthep led a group previously known as the People's Democratic Reform Committee from late 2013 to fight against the Yingluck government, ramping up pressure before the military staged its coup in May 2014.
It is one of the most divisive forces that the government has invited to take part in its ongoing bid for reconciliation.
Suthep said via his Facebook Live on Monday that political party reform would be among the main topics the group would propose to the committee.
He said political parties must belong to people in modern politics, and this must be addressed in relevant laws. To achieve this, a number of political party founders must be scrutinised as well as their financial contributions.
Suthep said it could involve at least one per cent of eligible voters to start with, and they as well as other party members must be the ones who select party executives as well as MP candidates to be fielded in an election. This would be a similar approach to a primary vote, he added.
With these measures, political parties would truly belong to the people, he said.
The reconciliation talks between the committee and political parties and blocs will be wrapped up by April before a social contract is made among them, based on what is discussed and agreed.