The South Australian government has urged Adelaide bus drivers and their employer to return to negotiations to avoid a strike next week.

Drivers for the privately-operated SouthLink, which runs services in Adelaide’s north and south and in the Adelaide Hills, have voted to strike for 24 hours on either Tuesday or Wednesday next week over a pay and conditions claim.

Industrial Relations Minister John Rau said the state government was concerned that the dispute had escalated, and urged the parties to return to negotiations.

“This is a matter between the union and the bus company. The state government is not a party to the issue,” he said in a statement on Monday.

“However, we are concerned about the impact this further escalation will have on commuters.”

The drivers have been offered a three per cent annual pay rise along with action to address safety concerns.

The remaining sticking point in negotiations centres on rostering.

Transport Minister Stephen Mullighan says contingency plans are being prepared to minimise the impact of the strike on commuters.

He says patronage will be lower because of school holidays and the strike falling in the period between Easter and the Anzac Day holiday.

The government says SouthLink will aim to cover services where possible with non-union drivers.