Two former administrators of the US Environmental Protection Agency (EPA) under Republican presidents have said they support the Democrat Hillary Clinton over Donald Trump.

In a joint statement, William D. Ruckelshaus and William K. Reilly believe Mr Trump’s energy policies prove “a profound ignorance of science and of the public health issues embodied in our environmental laws”.

Mr Ruckelshaus was the first administrator of the EPA under President Richard Nixon and the fifth under President Ronald Reagan and Mr Reilly was administrator of the agency under President George Bush.

They added: “He hasn’t a clue about republicans’ historic contributions to science-driven environmental policy: the incontestable environmental improvements in the restored lakes and rivers, the acid rain controls, the reduction of key air pollutants by 70% 80 and 90% and the sharp decline in pollution from automobiles even as their numbers more than doubled.

Their statement published in Ms Clinton’s website also said Trump “would set the world back decades”.

They went on: “That Trump would call climate change a hoax—the singular health and environmental threat to the world today—flies in the face of overwhelming international science and the public conviction and commitment of almost 200 national governments that adopted the Paris Agreement on climate change in December 2015.

“Our leadership was essential to that agreement.”

Mr Ruckelshaus and Mr Reilly believe Hillary Clinton is the right choice as she “understands that environmental protection is a public health issue and she recognises the threat that climate change represents to the world”.

They said: “For us, there is simply no choice in this election. We Republicans should be shocked, outraged even, at the prospect that all this progress, this legacy will be repudiated and rolled back by Donald Trump.

“This is a hugely consequential election; the stakes are that high. That is why as Republicans, we support Hillary Clinton for President.”