Day-ahead gas prices were up 1.25 pence at 31.50 pence per therm by 0830 GMT

Within-day gas prices also rose 1.45 pence at 32.25 p/therm

Traders said the rise in prices was mostly supply driven, as flows from Norway stayed at low levels as did output from wind turbines

The system is undersupplied with demand forecast at 201.9 million cubic metres (mcm) and flows at 186.9 mcm/day, National Grid data showed

Demand was 21.9 mcm above the seasonal norm

Norwegian gas flows to Britain remained low, slipping to 36 mcm/day from 38 mcm/day on Friday, as flows via the Langeled and Vesterled pipelines maintained Friday's low volumes

Peak wind power generation is forecast at 3 gigawatts (GW) and is expected to stay flat on Tuesday, National Grid data showed

Average daily temperatures are forecast at 13.0 degrees Celsius and staying flat on Tuesday before rising to 13.5C over the weekend, Refinitiv Eikon data showed

Britain received two LNG tankers on Sunday and expects four more to arrive by May 27

The June contract was up 0.50 p at 30.70 p/therm

Day-ahead gas prices at the Dutch TTF hub were down 0.09 euro at 12.98 euros per megawatt hour

The benchmark Dec-19 EU carbon contract was down 0.05 euro at 24.95 euros per tonne.