President Macri's coalition 'ahead' in crucial Argentina mid-term election
Argentina's President Mauricio Macri's coalition looks to be on course to make significant gains in the country's congressional elections.
Partial results show his centre-right alliance leading in the capital Buenos Aires, and in 15 out of 23 provinces at 22:00 local time (01:00 GMT).
A strong showing would enable Mr Macri to complete his economic and institutional reforms.
More than 78% of registered voters took part in the mid-term election.
More than 33 million Argentines were eligible to take part in the vote, which saw a third of seats in the Senate contested, along with half of those in the lower house of congress.
Mr Macri was elected by a narrow margin two years ago and he doesn't have an outright majority. This election is being seen as a test of his ability to win re-election in 2019.
The most closely-watched race is in the province of Buenos Aires where the centre-left former President, Cristina Fernandez de Kirchner, is standing for the senate.
Although trailing Esteban Bullrich, who was Mr Macri's education minister, second place was enough for the 64-year-old to win one of the province's three Senate seats, under Argentina's list system.
Graciela Mantilla, a 60-year-old housewife in Buenos Aires province, told Reuters news agency Ms Fernandez was the only alternative to "Macri's anti-people policies".
Ms Fernandez has been critical of Mr Macri's record in office, saying his policies have increased poverty and inequality in Argentina.
But sceptics say she is running for the Senate to get immunity from prosecution for the next six years.
She has been charged with illicit association and fraudulent administration.
She has repeatedly denied the charges and said that illicit association "is a legal concept that has been used by all dictatorships to persecute their political opponents".
Ms Fernandez served two terms from 2007 to December 2015. She succeeded her husband, the late Nestor Kirchner, who was in power from 2003 to 2007.