Labour will hold a vote in the Commons on Tuesday to pressure the government into tackling sewage dumping by water companies.
Environment Agency data shows sewage was dumped every two-and-a-half minutes on average since 2016, according to the Opposition.
The party said this amounted to 1,276 years’ worth of raw sewage going into rivers, lakes and the sea over a seven-year period.
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Labour’s shadow environment secretary, Jim McMahon, will use an opposition day motion to debate his Water Quality (Sewage Discharge) Bill, which would introduce automatic fines on water companies who dumped sewage.
It would also set legal requirements to monitor all sewage outlets – with fines for firms who don’t follow the rules – and set a legally binding target to reduce dumping events.
But without support from the Conservative benches, the measures will not become a reality.
Mr McMahon said: “It is clear that we have a Tory government that has run out of ideas, only regurgitating old announcements that do nothing to end sewage dumping.
“That is why Labour has brought forward legislation to clean up our water system.
“Tory MPs have an opportunity to support Labour’s Water Quality Bill which will put an end to sewage dumping once and for all.
“Their constituents will be watching to see if they will put the best interests of our country before their party.”
The Liberal Democrats are also backing the motion, with their environment spokesperson Tim Farron calling it “judgement day” for Tory MPs.
“Conservative MPs have spent the past year blocking tough new laws on water companies,” he added. “They are trying to take the British public for fools with tough talk and no action.
“Communities across the country have had enough of Conservative MPs who would rather protect water firms over their local environment.”
But environment secretary Therese Coffey claimed Labour’s bill was “ill-considered”, and attacked Labour’s own record in Wales where they are in power.
“Labour have turned a blind eye to raw sewage being dumped almost twice as often in Wales where they are actually in government,” she said.
She added: “They’ve turned Welsh waters into open sewers whilst playing politics in England. It’s clear they haven’t even read the government’s plan.”
She also defended her own party’s record on the issue, adding: “It was a Conservative government that introduced 100% monitoring of storm overflows.
“We’ve brought forward stronger regulations, tougher enforcement and the largest water infrastructure programme in history – an expected £56bn investment – and we will make fines unlimited so that the polluter always pays.”