Argentina's first lady and presidential candidate, Cristina Fernandez de Kirchner, has introduced her running mate for the 28 October vote.
Cristina Fernandez is promising jobs and economic security
Ms Fernandez, the wife of incumbent president Nestor Kirchner, presented Julio Cobos, the governor of Mendoza province, at a campaign rally.
Mr Cobos has broken from an opposition party to run with Ms Fernandez.
She is currently ahead in opinion polls and if elected would become Argentina's first elected woman president.
"It's Presidenta, get used to it: Presidenta," she told a crowd of several thousand supporters at Luna Park in Buenos Aires.
"I know that you are used to men but it's good to get accustomed to women too."
Ms Fernandez spoke of forming a coalition government and said her running mate represented the change needed for Argentina to continue to grow.
She also had praise for her husband who was elected president in 2003.
"This man that is seated there who is the Argentinean president, when he started his presidency he decided that the story must be changed and every man and women must be summoned."
Mr Kirchner is credited with bringing Argentina back from the brink of economic collapse since he took office.
From the start, Ms Fernandez, who is also senator for Buenos Aires, has sought to link herself closely to his management of the economy, says the BBC's Will Grant, in Buenos Aires.
She has promised jobs and economic security.
Argentina's weak and divided opposition has failed to capitalise on a series of corruption scandals that have hit the government, correspondents say.