GARD chairman Derek Stork, a former nuclear physicist, feared there was now a ‘strong possibility’ that Thames Water will favour the reservoir in its final document.

Writing in a GARD newsletter this month, he said: “They have either ignored, or over-ridden with dubious arguments, the majority of critical comments coming from stakeholders like GARD.

“Other [water] sources are less costly, less damaging to the environment, less disruptive to local communities and more robust against climate change.”

About 90 per cent of the Abingdon Reservoir water would benefit London, with the remainder shared between Swindon and Oxfordshire.

Thames Water believes Oxford will be left with a shortfall of one million litres of water per day by 2020 if no action is taken.