The invitations were sent today and that Abhisit Vejjajiva, Democrat Party leader, would discuss the new constitution on Nov 24.
Phra Buddha Isara, a monk who earlier led political demonstrations against the previous government, will meet him to exchange views on the new constitution tomorrow.
"I invite all parties, groups and sectors to give information. This includes the Pheu Thai Party which reportedly will not join [the process]. We are open to all groups. Your participation will be good and your opinions will be considered but if you are unwilling to participate, no one can be forced," Mr Borwornsak said.
Young people can participate through a subcommittee that he will form, he said.
He acted in response to the request from the Youth Network for Students to participate in the charter drafting process. The network has proposed the minimum age of representatives in the lower house of Parliament be lowered to 18 instead of 25 years.