The rand and government bonds weakened on Wednesday, giving up earlier gains, after the ruling African National Congress Party (ANC) rejected calls for President Jacob Zuma to quit.
Zuma's decision last week to fire a respected finance minister rattled markets and led to the country's debt being downgraded to junk status by S&P Global Ratings.
The rand firmed in earlier trade over mounting calls for Zuma to step down from unions, religious leaders, civil society and the opposition.
But the ANC rejected the calls, and at 0943 GMT, the rand traded at 13.8000 per dollar, 1.25 percent weaker from Tuesday's close.
The yield for the benchmark government bond due in 2026 rose 7 basis points to 8.985 percent.