Ancient woodlands covering an area larger than 12,700 football pitches are threatened with destruction to make way for new building developments and the controversial high-speed rail link.

Analysis by the Woodland Trust has revealed that at least 350 woods, which have all been a feature of the landscape for more than 400 years, could be lost or permanently damaged under plans to build housing, roads, quarries and the £33 billion rail route.

The scale of the threat, which the group says is the greatest in the 15 years since ­it began recording ancient woodlands at risk,