Keheliya Rambukwella, the Minister of Information, was responding to a query on the Tamil National Alliance (TNA) in the backdrop of a mediation bid by South Africa to achieve national reconciliation in the island.
"No they are not the sole representatives of Tamils. There are Tamil groups who oppose them and also there are other Tamil political parties represented in parliament", Rambukwella said.
"We can't engage in talks with TNA solely. Then it will be seen as acceptance of them as the sole Tamil representatives."
Ramaphosa is to meet with the TNA and the government with a view to help achieve reconciliation.
The South African initiative on the resolution of the Tamil question in Sri Lanka dates back to August, 2012 when Ibrahim Ibrahim then deputy minister of international relations visited Sri Lanka.
The South African government has emphasised that lasting peace could be achieved when the reconciliation process is underscored by an inclusive dialogue that addressed rights and freedoms of Sri Lankan Tamils.