Nepal's King Gyanendra has been stripped of his right to veto laws, after a unanimous vote by parliament.
King Gyanendra gave up absolute rule after weeks of unrest
MPs said all authority the king once had in parliament had been eliminated.
He will no longer be able to reject legislation passed by parliament, and lawmakers will not need to seek his approval when signing bills into law.
King Gyanendra agreed to reinstate parliament in April, after giving into popular demand that he cede absolute rule of the country.
The law was passed late on Saturday.
"The concept of king in parliament has been abolished through law," legislator Ram Baran Yadav said.
Raghuji Panta, an MP for the Communist Party of Nepal, said the king's role was now "totally ceremonial".
"With the approval of the regulation, a new rule has been made that full executive power of the state is centred on the council of ministers and the house holds legislative power," the speaker, Subash Nemwang, said.
The law is the latest move by parliament to cut King Gyanendra's powers.
Last month, MPs voted to strip the king of his command over the army, and of his legal immunity and freedom from paying taxes.
King Gyanendra gave up absolute rule after weeks of mass protests, in which at least 14 people died.