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Michael Gove says water firms "have much more to do to tackle leakage"
Michael Gove has summoned water company bosses to explain why they have failed to meet leakage targets, amid one of the driest summers for years.
The environment secretary said customers expect a "reliable and resilient water supply".
It comes as farmers are due to discuss the effect of the extensive heatwave on food supplies at a "drought summit".
It has been the driest summer in the UK since 1961 with rainfall on Thursday and Friday the first in weeks.
Water levels are low in some reservoirs and supplier United Utilities (UU) has said it will introduce a hosepipe ban affecting seven million people in the north-west of England from 5 August.
Mr Gove said water firms "have much more to do to tackle leakage", adding: "That is why I have repeatedly made clear that companies must improve and recently wrote to them to outline my expectations during this period of dry weather.
"Next week I will ask the chief executives of the water companies that have failed to meet their leakage targets to a meeting at Defra [Department for the Environment, Food and Rural Affairs) to discuss how they are going to address this serious issue and improve their performance."
UU has been accused of "wasting" 430 million litres of water every day from leaks.
The GMB union said its research showed that the supplier was allowing 175 Olympic-sized swimming pools' worth of water to go "down the plughole" every day.
Continued dry weather could see further hosepipe bans
Earlier this month, UU said "reducing leaks is a top priority".
At separate talks with government officials, chaired by National Farmers' Union (NFU) president Minette Batters, irrigation water shortages, a lack of fresh forage for animals and growing conditions for cereal crops are to be discussed.
Ms Batters will sit down on Wednesday with Defra officials, rural agencies and farming charities after a month that has seen England receive just 15% of its long-term average rainfall.
She described the situation as "hugely challenging" for all sectors of farming, warning that the thunderstorms and showers some areas are receiving "won't mitigate the many issues farmers are experiencing".
She said: "There could be serious concerns for many farmers if this extended spell of warmer, drier weather continues as the long-range forecast suggests."
Those due to attend the summit alongside Defra include the Environment Agency (EA), Natural England, the Rural Payments Agency (RPA) and farming charities RABI and Farming Community Network, the NFU said.
The EA said it has responded to 44 "significant" environmental incidents since the end of June, including moorland fires, algal blooms, dry boreholes, low river flows and fish rescues as the hot, dry weather continues to grip.
The last month of dry, hot weather followed the driest June since 1925, according to the EA. It has caused the water level in many reservoirs to fall dramatically.