While diesel will come down in June, petrol is set to rise once again.

Following two months of punishing increases, June could have seen some much-needed fuel price relief. While diesel is still looking set for a significant decrease, the phase-out of Treasury's fuel tax relief measures means that a petrol price increase is likely.

Late-month data from the Central Energy Fund shows that the price of petrol should theoretically decrease by between 25 cents (93 unleaded) and 21 cents (95 unleaded) from the beginning of June.

A far more significant over-recovery has developed for diesel, with the same data set pointing to decreases of between R4.60 for 50ppm and R5.29 for 500ppm.

However, the government has indicated that the fuel tax reprieve, announced at the beginning of April, will be halved from June 3 before being phased out at the beginning of July. This means an additional R1.50 needs to be worked into the petrol price and R1.96 into diesel.