JAKARTA - President Joko Widodo's rivals at the upcoming election have taken aim at his administration's economic policies, expressing concerns over the weakening of the Indonesian rupiah amid global uncertainty.

"We are gravely concerned with the endless weakening of the rupiah," said retired army general Prabowo Subianto and his running mate for the 2019 presidential polls, Mr Sandiaga Uno, in a statement sent to The Straits Times on Saturday (Sept 8).