Sri Lanka's main opposition accused the government Thursday of awarding contracts to a World Bank-blacklisted Chinese company and said it would not honour the deals if it regains power.

The United National Party (UNP) said the government had recently awarded a contract to the state-owned China Communications Construction Company Limited (CCCC) for a new port city in the capital Colombo despite the World Bank move.

"The government has given this project to a company which is banned by the World Bank due to corruption," UNP spokesman Harsha de Silva told reporters.

"We never thought that the government has been dealing with a company that has been debarred by the World Bank."

He said a future UNP government would not honour transactions with the firm.

There was no immediate comment from the CCCC, but Sri Lankan government spokesman Keheliya Rambukwella denied any corruption.

"There is no corrupt practice involving this company in respect of our transactions," Rambukwella told reporters.

The World Bank in a statement posted on its website from 2011 said the CCCC and its subsidiaries had been debarred till January 2017 for fraud in Philippine roads projects.

Chinese companies have emerged as key infrastructure partners of Sri Lanka and have already built air and sea ports, highways and railways.