Weakening environmental protections after Brexit would damage Britain’s reputation internationally, the United Nations (UN) has warned.

Environment Secretary Michael Gove must keep his promise to deliver a “green” exit from the European Union, senior official Erik Solheim urged.

Campaigners warned earlier this month that the environment and countryside will have less protection after Brexit under plans unveiled by the Government.

Mr Solheim, executive director of the UN’s environment programme, said it was “incredibly important that the UK keeps the environmental standards it has had under the European Union”.

In an interview with the Observer, he said: “Michael Gove promised that would happen – that there would be no reduction of standards of any sort.

“He even added that any change would be to better standards. There was a strong commitment to that from the government.

“Some of the opponents of the government had doubts about such statements, but that is the stated position from the government and it is a very good one.

“Any dilution and the UK reputation would be damaged. People in government need to make sure that does not happen. We need to make sure they have those standards or improve them, or meet the ones under the European Union.”

Environmental measures from improving air and water quality to protecting endangered species are currently overseen by the European Commission and underpinned by green principles across the EU, such as “the polluter pays”.

Mr Gove insisted earlier this month that new legislation would ensure environmental protections are not weakened as Britain quits the EU and a new watchdog will hold Whitehall to account for looking after landscapes and nature.

Campaigners warned that the regulator must have powers to take the Government to court if it fails to deliver on green policies and raised concerns over protections for action on climate change.