Robert said: "I am deeply concerned at reports that Thames Water has been routinely releasing sewage from Witney Sewage Treatment Works over the last couple of weeks when we have not experienced any heavy rainfall.
"I have therefore written to the Chief Executive of Thames Water to demand an explanation for these spills, which highlight just how vital it is for the expansion of Witney STW to be delivered urgently.
"I am also following up with the Environment Agency to ask them to investigate whether these spills breach Thames Water's permit conditions. I have been clear that illegal spills which harm our environment must be punished in the strongest possible terms."
A copy of Robert's letter to Sarah Bentley, CEO of Thames Water, can be read through the link below.