Veteran Tamil National Alliance (TNA) leader Rajavayoti Sampanthan counter-accused the government for the standoff.
The Tamil party had made several overtures but the government had repeatedly reneged on agreements reached at the direct talks with TNA, Sampanthan said.
He asserted that the 2011 talks with the government failed as the government ignored action required to implement agreements reached between the two parties.
This was following a call by President Mahinda Rajapaksa for an all-party parliamentary select committee (PSC).
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External affairs minister G L Peiris had told the UN Human Rights Council sessions in Geneva that TNA's intransigence had led to the deadlock.
Sri Lanka is facing a third UNHRC resolution in as many years, censuring the country on its lack of progress on human rights accountability and reconciliation with its Tamil minority after the civil war ended with the defeat of the LTTE in May, 2009.
India had backed the previous two resolutions.
When the PSC started its deliberations last year, the TNA and the opposition parties had boycotted it.
Giving reasons, Sampanthan said that the party had skipped the PSC as the government was not keen on a political solution and failed to indicate its willingness by implementing agreements reached during government-TNA talks.