LISBON: Former Portuguese prime minister Antonio Guterres was nominated to be the next UN secretary-general on Thursday.

An engineer by training and fervent Catholic, Guterres, 67, fought unflaggingly for migrants' rights over a decade as UN High Commissioner for Refugees from June 2005 to December 2015.

Guterres repeatedly warned that millions of refugees fleeing conflict in Syria, Iraq, Afghanistan and elsewhere would turn to Europe if nations such as Turkey and Jordan did not receive more help to cope with their refugee populations.

“When people say they cannot receive Syrian refugees because they are Muslims, those that say it are supporting terrorist organisations and allowing them to be much more effective in recruiting people,” he said in December just before he stepped down as UN refugee chief.

Former Portuguese president Anibal Cavaco Silva said earlier this year that Guterres had “left a legacy” at the refugee agency “that means today he is a respected voice and all the world listens to him”.

Born in Lisbon on April 30, 1949, Guterres joined Portugal's Socialist Party following the country's 1974 “Carnation Revolution” which put an end to nearly five decades of dictatorship.

Elected as a lawmaker in 1976 in Portugal's first democratic election following the revolution, Guterres quickly earned a reputation as a gifted orator.

Fluent in English, French and Spanish in addition to Portuguese, in 1992 he became secretary general of the Socialist party, in opposition at the time.

Guterres led the party to victory in the next general election in 1995, becoming prime minister.

Portugal was undergoing rapid economic growth at the time and enjoying nearly full employment, which allowed Guterres to set up a guaranteed minimum income, one of his government's flagship measures.

Staunchly pro-EU, Guterres made meeting the criteria for membership in the euro-single currency area a priority and Portugal was among the 11 nations that adopted the common currency when it was launched in 1999.

On his watch the Socialists were re-elected in 1999, again without an absolute majority in parliament.

His stewardship of Portugal's turn at the helm of the rotating presidency of the European Union during the first half of 2000 was considered a success.

Guterres resigned after the Socialists took a drubbing in local elections in late 2001, saying he wanted to prevent the country from falling into a “political swamp”.

He also abandoned Portuguese politics to focus on a diplomatic career abroad.