There are calls for Lidl to pull plans to sell massive pools for the back garden next week.
The pools need up to 7-and-a-half thousand litres of water but the supermarket chain says they contain a filter so they don't need to be drained and filled every time they're used.
However Irish Water is urging people to conserve supplies during the heatwave.
The utility says restrictions will be unavoidable if the hot weather continues as forecast.
Green Party leader Eamon Ryan says the system is already under pressure and he wants Lidl to play its part: 'It's very tempting to be lounging out in a pool, but we're running short of water, we've got to be careful, we could go into a long dry spell. So I think Lidle should play their part'.
A spokesperson for Lidl says 'The water does not need to be emptied and refilled after each use.'
'This offering is no different to products on sale at this time of year from other retailers'.