The military defeated the rebels after killing their leadership May 18, but the resettlement process has been delayed.
The government claims de-mining work has not been completed, but the opposition says the refugees are being held back for political reasons and to obtain foreign aid.
'De-mining needs special expertise. It is a slow process and has to be done diligently and carefully. The area is heavily mined,' Wickremanayake said.
Opposition United National Party member Lakshman Kiriella told parliament that no opposition MPs were allowed to visit the refugee camps.
The government vowed to resettle nearly 80 percent of the 285,000 refugees in the camps before the end of the year.