Thames Water says it is planning to introduce a hosepipe ban for London boroughs but won't reveal exactly when.

The company announced today that it has put both the Environment Agency and industry regulator, Ofwat, on notice that controls on water use are imminent. 

Such a ban would outlaw the use of hoses for watering the garden and washing cars. Any failure to abide by the rules could result in fines of up to £1,000. 

In parts of the country where bans are already in place, residents are being asked to snitch on neighbours that are flouting the rules. 

The details of the extent of the ban have not yet been announced by Thames Water. In some areas there are exemptions to allow people to water newly laid turf and even, in some circumstances, to fill hot tubs. 

A Thames Water spokesman said: "Given the long-term forecast of dry weather and another forecast of very hot temperatures coming this week, we are planning to announce a temporary use ban in the coming weeks. 

"We have written to the Environment Agency to update them on our approach and informed Ofwat. 

"The timing is not confirmed due to a number of operational and legal procedural requirements but we will be updating our customers, partners, regulators and stakeholders at the earliest time to ensure a co-ordinated approach. 

"In the meantime, we continue to urge our customers to only use what they need for their essential use."