British wholesale natural gas prices rose Monday on a combination of tight supply and stronger demand.

Natural gas prices for delivery on Tuesday were trading around 88 cents per therm at 9 GMT, up 3 pence since Friday afternoon, and prices for within-day delivery were up 6.68 cents to 80.9 cents a therm.

According to predictions by the British energy company National Grid (NYSE:NGG), natural gas demand in Britain was expected to be around 50.2 billion gallons on Monday. But with flows seen at 44 billion gallons, the system was undersupplied by 6.2 billion on Monday, which subsequently raised prices on account of the  higher imports and storage withdrawals that were required.