Ashby MP Andrew Bridgen has defended his decision to vote against a bill placing a legal duty on water companies to reduce raw sewage discharges into rivers.

He claims the amendment would have cost the Government: 'Just short of a trillion pounds or four HS2 lines'.

A proposal from the Lords to the Environment Bill was defeated by 265 MPs' votes to 202 last week.

Water companies discharged raw sewage into rivers in England more than 400,000 times last year and for more than three million hours, according to figures published by the Environment Agency.

The BBC website reports a number of MPs have defended their decisions.

Mr Bridgen, Conservative MP for North West Leicestershire, was among those to vote against it.

But he has explained on his own website why he made that decision - and says the cost involved would have been huge.

He says the work would involve the spending the equivalent of four HS2 lines.

The MP wrote: "The amendment itself called for the entirely laudable and absolutely correct premise that raw sewage should not – under any circumstances – be discharged into our watercourses and seas.

"Who could disagree with such an idea? Certainly not me.

"But when the amendment was considered by parliament last week, I did indeed vote against it.

"This is where Righteous Fibdignation comes into play, so I want to set the record straight as to exactly why I did so.

"I, and I am sure every other Conservative MP, wants to see an end to the discharge of raw sewage into our streams and rivers – something that has been happening for many years – but what an internet meme or a left-wing blog will never tell you is that getting to this point involves overcoming a monumentally large task.

"At the current time. sewage should only ever be discharged into watercourses when our sewerage system cannot cope.

"Effectively to completely stop overflow discharges we as a country would need an entire new, expanded or 'backup' sewerage network.

"The most optimistic estimates for implementing the works needed to make such changes are £150 billion, the most conservative £600 billion – in other words at least four HS2 lines!

"I don't believe that taking on a spending commitment larger than the GDP of many countries should ever be done by accident.

"Yet the hereditary Duke of Wellington's amendment to the Environment Bill would have seen not only that, but also an obligation coming into force to prevent sewage discharges as soon as the bill received royal assent.

"In other words had I supported the amendment, I would have been committing our Government to underwrite a bill of a figure not far shy of One Trillion Pounds.

"Not only that it would be on a new national infrastructure project that had to be delivered in a timescale of just months, meaning its design, planning application and building would have to be complete by next summer just prevent the law from being broken!

"There was no way any responsible Member of Parliament could or should have voted for Lords Amendment 45 in its original state.

"Yet in doing so I and my colleagues have supposedly become enemies of our environment.

"As ever our opponents will always make cheap points – and stretch the truth - to gather a social media storm.

"The truth is though when you are the grown ups in the room you don't get to spend £600 billion without at least fully considering it. Even if that means you can't always vote for pie in the sky proposals."

You can read Mr Bridgen's response in full HERE.