South Africa’s rand drifted lower on early Tuesday, giving back some gains after rallying to its firmest level in a week as some investors bet a no-confidence vote by secret ballot against President Jacob Zuma could see him ousted.

At 0650 GMT the rand was 0.13 percent weaker at 13.2375 per dollar compared with an overnight close of 13.2200 in New York. The rand rose to 13.1825 on Monday, its firmest since July 31, soon after the parliamentary speaker allowed a secret ballot in the opposition-sponsored vote taking place later on Tuesday.

Zuma’s critics hope the secret ballot will embolden a significant number of the 249 African National Congress lawmakers in the 400-seat house to vote against a president beset by allegations of corruption, which he has consistently denied.

Analysts said it was unlikely the motion would succeed but that the possibility was driving sentiment in the short term, and that trade would be subdued leading up to the vote.

Stocks were set to open higher at 0700 GMT, with the JSE securities exchange’s Top-40 futures index up 0.2 percent.

In fixed income, the yield for the benchmark government bond due in 2026 was down 0.5 basis points at 8.57 percent.