New habitats are already being developed

The plan to create 5,000 hectares of new wetlands was unveiled on Friday by the Royal Society for the Protection of Birds (RSPB).

The proposed wetlands, stretching from Lincoln to Cambridge, would be equal to the size of Loch Ness.

The RSPB hopes it will provide a lifeline for England's vanishing species

The scheme aims to build on the RSPB's work on fen projects in Cambridgeshire, Suffolk, Norfolk and Lincolnshire.

The fens once covered 5,000 square kilometres in East Anglia.

We have already made a start, lost fens have been recreated, promising early benefits for rare nesting birds such as bitterns RSPB chief executive Graham Wynne

The fens were home to a spectacular array of wetland wildlife, some now lost from the UK entirely such as the large copper butterfly and nesting black terns.

But four centuries of drainage have almost caused the complete destruction of this area.

'Just the beginning'

The RSPB's vision for wetlands in the fens is to be unveiled at the recently recreated RSPB Lakenheath Fen, on the Suffolk and Norfolk border.

RSPB chief executive Graham Wynne said: "We have already made a start, lost fens have been recreated, promising early benefits for rare nesting birds such as bitterns.

"This is just the beginning, by creating the right habitat small and vulnerable populations of black tailed godwits can be given a secure future and, in time, long lost birds of the fens, such as cranes and spoonbills, may find a home once more."

An RSPB spokesman said eastern England provides some of the biggest opportunities for wetland creation in the UK.

He said the society is already creating new freshwater wetland habitats in the Cambridgeshire fens at the Hanson-RSPB wetland project at Needingworth, the Nene Washes near Peterborough and at Lakenheath Fen.

The group also manages wet grazing marshes at the Ouse and Nene Washes.