Conservation groups have criticised the government for failing to set a definitive legal target to halt the decline of nature by 2030.

Environment secretary George Eustice announced last month that the Environment Bill would be amended to include a species abundance target for 2030.

He described the move as a huge step forward which he hoped would spur action to address the biodiversity crisis.

But environmentalists say the published amendment falls far short of the action needed to protect nature and weakens the UK's position to negotiate strong deals for nature and climate action at international talks.

Rather than setting a firm commitment to halt the decline of species by 2030, the amendment does not set a date to meet the goal, they warned.

Instead, under the draft law, a new species target for 2030 must only "further the objective of halting a decline in the abundance of species".

Now, a coalition of 35 conservation groups, including The Wildlife Trusts, has written to Boris Johnson calling for the government to set an "unqualified target to halt the decline of species by 2030" backed by strong laws to protect wildlife sites and species.

Nik Khandpur, joint interim chief executive of Norfolk Wildlife Trust, said: "It has been our expectation for some time that this bill could make a real difference to wildlife but only if it is courageous in its approach to nature recovery, including essential legislative protection.

"Establishing a clear and decisive target to halt the decline of species by 2030 is a key component to ensuring the bill has meaningful impact."

Dr Richard Benwell, chief executive of the Wildlife and Countryside Link coalition of conservation groups, described the draft legislation as "a run-of-the-mill bill, not the ground-breaking law that was promised."

"The prime minister is saying all the right things about averting an ecological crisis at the G7, but the Environment Bill must be urgently strengthened to give substance to his rhetoric," he said. "That means rapid action to introduce a definitive target to halt the decline of wildlife by 2030."

Mr Eustice said: "We are heading into the G7 summit, and later this year COP26, as leaders on the world stage when it comes to the protection of the environment and nature. Claims to the contrary are wrong.

"Our landmark Environment Bill will include a duty for new, historic legally-binding target for species abundance for 2030, aiming to halt the decline of nature."