The seats were held by Leung Chung-hang in New Territories East and Yau Wai-Ching in Kowloon West.
The Department of Justice (DOJ) has moved to challenge four more lawmakers over the validity of their oaths.
After the gazette, the government will arrange for a by-election within four to six months.
Regular talks expected between the central government and members of the opposition camp may boost support and reduce tension in the city, experts say.
Pair said that they are considering taking the case to a higher court.
Beijing has never budged on matters of principle, as have been evidenced by many historical events.
The world is changing and the liberal international order dictated by the West is crumbling, while the Western political system is struggling in the death grip of an unprecedented crisis.
NPCSC chairman expresses his faith in the majority of the Hong Kong people.
Zhang Dejiang expressed his hope that Hong Kong compatriots would safeguard the region's social and political stability.
The DOJ is expected to file the litigation later this week or early next week.