Girija Prasad Koirala, who has died aged 85 of a chest infection, played a dominant role in Nepalese politics from 1990 up to the installation of a Maoist-led government in April 2008, serving five times as prime minister. Politically active since the late 1940s, he was the youngest of three brothers to hold that office, and the last significant survivor of the generation of political activists who, in 1950, brought down the shogunate — with the Rana family in control of the power of the monarchy as hereditary regents — and began the country's first experiment with parliamentary democracy.

Though Koirala was a centrist, he went on to become a champion of the peace process that saw the abolition of the monarchy and brought the Maoists into electoral politics after a civil war in which more than 13,000 people died. At the time of his death, he was still trying to secure a new constitution.

He was born in the north Indian state of Bihar, where his father, Krishna Prasad Koirala, a hill Brahman who had angered Maharaja Chandra Shamsher Rana, was in exile. Though the family was permitted to return to Nepal after Chandra's death in 1929, Koirala was privately educated in India, and as a teenager, he followed his father and elder brothers Matrika and Bisheshwar (“BP”) into both the Indian nationalist movement and the struggle against the Ranas in Nepal. In March 1947, he was an organiser of a strike in a jute mill at the border town of Biratnagar, and he was one of the leaders of the column that captured the town when the India-based Nepali Congress party launched its armed movement in November 1950.

After a settlement brokered by India at the beginning of 1951 transferred power from the Rana family to King Tribhuvan, Koirala worked in the Congress party organisation as head of the youth wing and joined the party's central working committee in July 1958. Like his brother BP, who had led the Congress government elected in 1959, he was imprisoned after Tribhuvan's son, Mahendra, abolished the parliamentary system in 1960 and replaced it with palace-dominated “Panchayat democracy”. In Mahendra's model, panchayats (traditional councils) were directly elected, sometimes on just a show of hands, at the lowest level, and the members at each level would elect the members of the next level up.

Released in January 1968, Girija joined his brother in self-imposed exile in India in 1971, returning to Nepal in December 1976. By early 1978, he was describing himself as general secretary of the party, probably after nomination to the post by BP, although he later claimed to have been elected in 1976. He campaigned for a return to multiparty democracy in the 1980 referendum that narrowly endorsed the panchayat system.

With his senior colleagues Ganeshman Singh and Krishna Prasad Bhattarai, the acting party president, Koirala was a member of the troika to whom BP entrusted the party shortly before his death in 1983. Generally more conservative than the other two, Girija was initially hesitant about the Movement for the Restoration of Democracy launched by Congress in spring 1990. However, the success of the street protests led to his appointment as prime minister in May 1991, when Congress won an overall victory in the election but interim prime minister Bhattarai failed to win in his own constituency. Koirala became the focus of protests by leftists and was soon at odds with both Bhattarai and Singh; internal party conflict centred mainly on patronage for ministerial appointments, though Koirala was felt by some to be moving too far from the socialist ideology of BP. In July 1994, he called mid-term polls, but he backed away from a showdown and agreed with Bhattarai that both factions should contest the election together. Congress nevertheless lost and the Unified Marxist-Leninists (UML), previously the main opposition, formed a minority government.

After helping engineer the fall of the UML government in September 1995, Koirala allowed his junior colleague Sher Bahadur Deuba to head a Congress-led coalition, while he succeeded Bhattarai as party president in May 1996. Deuba's administration, which witnessed the beginning of the Maoist insurgency, fell in March 1997 and was followed by two other unstable coalitions. Koirala regained the premiership in April 1998, first at the head of a Congress minority government and then in coalitions with the left.

In the campaign for the May 1999 election, Koirala secured party unity by endorsing Bhattarai as candidate for prime minister, but in March 2000 made use of his personal support among Congress MPs to supplant him. He cited as justification Bhattarai's failure to contain the Maoist insurgency, but he had no more success himself.

From February 2001 onwards, Koirala was the target of opposition disruption in parliament and protests over corruption. Early in June this was overshadowed by Crown Prince Dipendra's gunning down of King Birendra and eight other members of his family before his own apparent suicide. In July, when the army refused to follow his order to intervene and release 69 policemen abducted by the Maoists, Koirala resigned and was succeeded by Deuba, who began negotiations with the rebels.

After the Maoists pulled out of talks and attacked the army in November 2001, Koirala backed Deuba's handling of the crisis. However, in April 2002, it was reported that he secretly met the Maoist leader Pushpa Kumar Dahal in New Delhi. That summer the party's central committee, with a majority of Koirala's supporters, instructed Deuba not to renew the state of emergency. Deuba responded in May 2002 by requesting a dissolution and set up his own breakaway party. In October 2002, when Deuba sought the postponement of the elections, King Gyanendra dismissed him, and then appointed three governments on his own.

In February 2005, the king took control of the administration. Koirala was put under arrest, but was released in April and, in collaboration with leaders of other parties, reached an understanding with the Maoists in Delhi in November 2005. Joint protests in April 2006 forced the king to reinstate the dissolved 1999 parliament, and Koirala became prime minister again, leading a coalition which the Maoists joined in April 2007. Once the interim constitution was adopted in January 2007, Koirala began exercising the functions of head of state and later that year accepted a Maoist demand that Nepal be declared a republic, with only implementation of the decision left to the constituent assembly.

He probably delayed preparations for constituent assembly elections, originally scheduled for June 2007, hoping that support for the Maoists would ebb. There was a further delay because of demands by regional activists, and the challenge presented by the emergence of the Madhesi Janadhikar Forum (MJF) at the head of a powerful regional movement in the eastern part of the Tarai plains. Koirala, whose health had long been a problem, did not stand in the elections, which were finally held in April 2008 and which saw many of his relatives defeated in their stronghold in the eastern Tarai, while the Maoists became the largest party in the assembly.

Koirala had wanted to become first president of the new republic, but this was opposed by the Maoists. In mid-August he was replaced as premier by former rebel leader Pushpa Kumar Dahal, at the head of a Maoist-UML-MJF coalition. Following Dahal's resignation in May 2009, Koirala, who remained Congress party president, was involved in negotiations for the formation of a new UML-led coalition. Despite his poor health and delegation of day-to-day party administration to a nephew, he remained active almost to the end, failing to prevent a dilution of the powers of the party leader, but also meeting frequently with the Maoist leader. Koirala and Dahal both became members of the “high-level political mechanism” formed last January to try to resolve the continuing crisis over constitutional and security issues the interim constitution of 2007 was due to be replaced by a permanent constitution this May.

Koirala's wife, Sushma, predeceased him. His daughter Sujata, who served as minister without portfolio in his cabinet in 2008 and is foreign minister and deputy prime minister in the current coalition government, and his son Suresh survive him.—Dawn/The Guardian News Service