A legal challenge has been filed against the prime minister and Dewan Rakyat speaker over the limiting of the May 18 sitting to just the royal address.

Lawyer R Kengadharan and social activist D Arumugam, filed their writ of summons at the Kuala Lumpur High Court Registry early this afternoon.

According to the cause papers, the duo, among others, seek a declaration that the Parliament sitting, which is only slated to hear the Yang di-Pertuan Agong's speech, is unconstitutional.