UML's Vice President Ram Bahadur Thapa is among the 16 MPs in the House of Representatives on the proportional representation side. He became an MP from the number one list on the male side of the indigenous/tribal 'cluster'.

UML won 9 seats directly and got 16 MPs through proportional representation. Thapa is the most senior leader among the 16 proportional representation MPs of UML.

Thapa, a favorite of then Chairman Pushpa Kamal Dahal while in the Maoists, became equally beloved by Oli after joining the UML. In the 2074 BS representative elections, an electoral alliance was formed between the UML and the Maoists to unify the parties.

UML Chairman Oli and Maoist Chairman Dahal were engaged in a joint election campaign. Dahal's son Prakash died suddenly on 2074 BS. The election campaign continued even while Dahal was in mourning. Dahal deployed Thapa alongside Oli in that campaign. The rift between Oli and Thapa grew at that time. Oli has promoted Thapa, who speaks little but does not deviate from the official party line, to the UML.

After the unification of UML and Maoists in 075 Jestha, the Nepal Communist Party was formed. Oli and Dahal became the two chairmen of the NCP. The UML and Maoists brought 174 seats to the parliament of the NCP. In 074, Thapa became a member of the National Assembly.

Although there was an agreement that Oli would lead the government and Dahal would run the party, it did not last long. Less than a year after the formation of the NCP, a power struggle began between Oli and Dahal. When their power struggle reached the point of displacing each other, Thapa, who was in the central secretariat, supported Oli. At that time, Oli was the Prime Minister and Thapa was the Home Minister. Home Minister Thapa worked with the trust of the then Prime Minister Oli. This was the second major influence that Thapa had on Oli.

Oli was in the minority in the nine-member central secretariat of the then NCP. He was supported by leaders Ishwor Pokharel, Ram Bahadur Thapa and the then General Secretary Bishnu Poudel. Madhav Kumar Nepal and Jhalanath Khanal, Bamdev Gautam and Narayan Kaji Shrestha stood in Dahal's favor.

After December 2077, when the dispute in Kapa reached its peak and the party was on the verge of splitting, many former Maoist leaders sided with Dahal, but Thapa chose Oli. After Thapa emerged as the leader of the crisis, Oli has been moving forward. After the UML suffered a major defeat in the elections held on Falgun 21, Oli has re-entered parliament.

When the power struggle between Oli and Dahal was reaching its peak, the Supreme Court heard a petition in Falgun 2077 and restored the UML and the Maoists to their previous status. While leaders with Maoist backgrounds, including Dev Gurung and Pampha Bhusal, joined the Maoists, Thapa remained in the UML. The main reason for his stay in UML was his close relationship with Oli.

In the 11th UML general convention last Bhadra, it was difficult for a leader with a former Maoist background to reach the leadership. But Oli instructed the general convention delegates to 'use their power' to win Thapa and another leader Lekhraj Bhatta. Thapa was elected vice-president and Bhatta deputy general secretary.

Whether in the Maoists or in the UML, Thapa openly supports the institution. He was with Oli when he was in the NCP. Thapa stands in favor of the institution when there is internal conflict in the UML. This old habit of his continued until the 11th UML general convention in Bhadra.

Thapa was the home minister in Oli's cabinet from 2077 and until Asar 2078. After the 2007 Constituent Assembly elections, Maoist Chairman Dahal became Prime Minister and Thapa became Defense Minister in Asad 2007.

In April 2007, the Maoist-led government decided to dismiss the then Army Chief Rukmangat Katwal and appoint Army Chief Kul Bahadur Khadka as the new Army Chief. The then Defense Minister Thapa had taken the proposal to take action against Katwal to the Council of Ministers meeting. President Ram Baran Yadav overturned that decision and saved Katwal.

After the dispute between the government and the Nepal Army escalated, Maoist Chairman and then Prime Minister Dahal resigned on April 21, 2007. At that time, Maoist Chairman Dahal and Vice Chairman Baburam Bhattarai moved forward with the work of drafting a constitution through the Constituent Assembly, while another Vice Chairman Mohan Baidya had a different opinion. Thapa had sided with Baidya in that internal conflict. On 3 Jestha, 2069, the CPN (Maoist) was formed under the leadership of Mohan Baidya in Boudha, Kathmandu. A month later, in Asar, the Unified CPN (Maoist) was formally split.