Leaving Europe would be the most "bonkers" and "idiotic" thing the UK could do when it comes to protecting wildlife and preventing air pollution, a leading environmental lawyer has said.

Brexit could put a raft of environmental laws from keeping beaches clean to caring for important landscapes at risk, according to law organisation ClientEarth - which is taking the Government to court again over its failure to meet EU targets for air quality.

While the laws would remain in place in the aftermath of a vote to leave, a UK government outside of Europe would be able to repeal or change them, with concerns that nature protection would be abandoned in drives to cut "red tape".

Even if the UK left the EU but joined the European Economic Area (EEA), many of Europe's environmental laws, such as rules protecting birds and habitats, bathing water standards and the common fisheries policy, would not apply, ClientEarth said.

Important wildlife areas including the Severn Estuary, Salisbury Plain, the North York Moors, Rutland Water, the Farne Islands, the Cairngorms and Strangford Lough, are protected under the EU's Birds Directive.

And natural areas ranging from Ben Nevis and Glen Coe in Scotland to Wales' Cadair Idris and Cardigan Bay, the Lizard, Cornwall, Cumbria's River Eden and Epping Forest in Essex are protected under the Habitats Directive.

Speaking on a live online broadcast via Twitter and Periscope, James Thornton, chief executive of ClientEarth said: "If we do decide to leave the EU we'll be doing the most ill-considered - let me say bonkers, let me say stupid, let me say idiotic - thing we could be doing with respect to the environment."

He added: "If we left the EU but stayed in the EEA, we'd be bound by a great many EU laws but we would not be bound by nature protection laws or the common fisheries policy - that poses a really great threat to fisheries.

"Some environmental laws - water quality law, air quality law - would stay in place. But nature protection would not."

And he warned that the current air pollution rules were "pretty weak" and the Government was not even complying with them.

"So, are they likely to make stronger laws and comply with that? No chance.

"If we left, it would simply be an excuse not to take care of people in the UK affected by air pollution," he said.