Paul Chan, Hong Kong’s finance chief, announced the plans as part of the country’s budget last week, saying the money raised would fund “green public works projects”.

But the environmental group Green Sense warned Hong Kong’s investment in green projects could be an “empty concept” as the government had not defined what “green public works projects” were and there was no way for citizens to find out.

“There is no clear definition of ‘green public works projects’, and the public can never know what such projects are," the Green Sense response said.  

“‘Green public works projects’ is likely an empty concept, and the funds might eventually be used for more ‘white elephant’ projects.”

It added that the government’s previous green projects had been controversial, with the “extent of lawmakers’ supervision over these projects” being “disproportionate” and claimed they had caused environmental destruction.

Chan said the green bond programme would have a borrowing ceiling – the maximum amount of monies that can be borrowed - of HK$100bn.

The Hong Kong government also announced a separate HK$2.5m three-year pilot bond grant scheme in the budget, which will seek to cut issuer expenses by half and attract more investors.

The scheme includes a number of measures to develop the city’s bond market.

A government official told the South China Morning Post: “We hope to further expand the bond market in Hong Kong. We believe the HK$2.5m bond grant is pretty competitive.”

The source added the incentive was higher than the bond grant offered by the Singaporean central bank in June last year, which was aimed at encouraing the use of credit ratings by issuers in the Singapore dollar bond market. Issuers of Singapore dollar bonds can claim 100% of their credit rating expenses up to the limit of S$400,000.

White elephant projects refer to projects which are expensive, difficult to maintain or underused.