HDP lawmaker Idris Baluken said the decision had been made without consulting with local representatives in the Kurdish cities and was part of "the government's efforts to implement a security and military plan."
The government has said the new capitals in the two provinces will be Cizre and Gever, which according to the proposal have better infrastructure and geographic potential to serve the population.
"It is an undemocratic decision because people were not asked. And to make Cizre and Gever capitals is not for the sake of developing these cities, it's part of government's security and military plan," lawmaker Baluken said.
There are around half a million people in the province where Cizre now becomes the new capital city and about 300,000 in Gever province.
Sirnak which became a capital city in 1990 will also have its official name changed to Noah.
The official name of Hakkari will also be changed to Colemerg and the provincial capital will move from there to neighbouring Gever.
No official explanation has immediately been provided for the name changes.
"It will have a devastating effect on the economy in Sirnak which already has suffered under multiple curfews," head of the Sirnak Chamber of Commerce Usman Galish told Rudaw.
