LONDON: Britain, which hosts the UN climate summit later this year, lags behind key European nations in its issuance of so-called green bonds, lawmakers said Thursday.

Finance Minister Rishi Sunak had revealed his government's first sovereign green bond late last year to help fund environmental projects, as part of plans to get British carbon emissions down to net zero by 2050.

However, the initiative mirrors a policy that already exists in France and Germany, according to parliament's cross-party Treasury Committee.

"With the first issuance expected this summer, the UK is lagging behind other countries," it said in a report entitled 'Net zero and the Future of Green Finance'.

"For example, France's first green sovereign bond was issued in January 2017 and Germany's was in September 2020."

Worries persisted over the debt because it will have a higher overall cost than normal state bonds, the report added.

"Whilst concerns about the potential for green sovereign bonds to be a more expensive form of debt seem to have dissipated to a degree, the government should nonetheless set out its tolerance for them to be more expensive than other forms of debt," it said.

British Prime Minister Boris Johnson is due to host COP26, the UN's annual climate gathering, in Glasgow in November.