Kathmandu, Aug 18 : In a rare political development, Nepals first and fourth largest parties in the Parliament split on Wednesday following the promulgation of an Ordinance by President Bidhya Devi Bhandari. The Nepal government had on Tuesday recommended President Bhandari to amend the existing Political Party Act to relax the formation of new parties. Hours after Bhandari promulgated the Ordinance, Nepal's largest party in Parliament, Nepal Communist Party (UML), has split. The chairman of UML is outgoing Prime Minister K.P. Sharma Oli. The fourth largest party in the House, Janata Samajbadi Party, which has 32 lawmakers in the Lower House, has also split. Senior UML leader and former Prime Minister Madhav Kumar Nepal announced his split from the mother party and registered a new party -- Nepal Communist Party UML-Socialist -- on Wednesday with the Election Commision. Oli and Nepal have been arch-rivals in the party for a long time and there was deep discord, dispute and division inside the party between them for the past two years. Out of the 123 lawmakers, Nepal secured the support of 30 and formed a new party, which is also the part of the eongoing ruling alliance led by President of Nepali Congress, Sher Bahadur Deuba. After registering the new party with the Election Commission, Rajendra Pandey, a senior leader of the Nepal faction, said that after Oli failed to admit his mistake for dissolving the House twice and for failing to maintain the party unity, they finally decided to split the party. The Oli camp called it a " black day in Nepal's Communist movement". The amendment Ordinance stipulates that 20 per cent or more members of a parliamentary party and the central committee of a political party can split from their mother party. Before the amendment, provisions of the Political Party Act required dissidents to have the support of 40 per cent of members in the parliamentary party and the central committee to split from their mother party, The CPN-UML, which at one point boasted of two-thirds majority, has now split into two. The Sher Bahadur Deuba led-government had recommended the promulgation of the Ordinance to President Bhandari on Tuesday, in a bid to facilitate the registration of Nepal's party. Similarly, the fourth largest party in the House, Janata Samajbadi Party, has also split formally. A section of the party led by its Chairman Mahantha Thakur registered a new party with the Election Commission on Wednesday following the promulgation of the Ordinance. The Thakur faction has a long standing dispute with another Chairman, Upendra Yadav. Thakaur has formed a new party named Janta Samajbadi Party Nepal (Democratic). The Deuba government had introduced the Ordinance to secure majority for the government. Now, Nepal's new party will join the Deuba government. It is not sure whether Thakur's new party will join the new government, but it will continue to support the government, its leader Rajendra Mahato said. The other chairman of the Janata Samajbadi Party, Upendra Yadav, is all set to join Deuba's government. Another key alliance partner, Nepal Communist Party (Maoist Center) is already in the government. Its chairman is Pushpa Kamal Dahal 'Prachanda'. /IANS