The within-day contract was down 0.75 pence at 22.00 p/therm by 0926 GMT.
The day-ahead contract was down 0.63 pence at 22.00 p/therm.
Traders said Europe remains a possible destination for any LNG tankers diverted from China.
Benchmark Asian LNG prices hit record lows last week while China's top LNG buyer China National Offshore Oil Corporation (CNOOC) declared force majeure on some prompt LNG deliveries with several suppliers.
Six more LNG tankers were added to Northwest European terminal arrival schedules on Monday, with 23 tankers set to arrive this month.
Peak wind power generation in Britain is forecast at 14.1 gigawatts (GW) on Monday and 14.3 GW on Tuesday Elexon data showed.
Analysts at Refinitiv forecast demand for gas from power stations at 36 million cubic metres (mcm) on Monday, down 17 mcm on the previous forecast.
The March contract was down 0.88 p at 21.25 p/therm
The day-ahead gas price at the Dutch TTF hub was down 0.43 euro at 8.77 euros per megawatt hour.
The benchmark Dec-20 EU carbon contract was down 0.29 euro at 23.03 euros per tonne.