LONDON, June 27 (Reuters) - Dutch wholesale gas prices rose on Monday morning with fears over Russian and liquefied natural gas (LNG) supply buoying prices while British prompt prices fell on weaker demand for gas from power plants.

The benchmark Dutch wholesale gas contract for July delivery was up 1.50 euros at 131.20 euros per megawatt hour (MWh) by 0945 GMT, while the August contract rose by 3.85 euros to 132.70 euros/MWh.

Russian gas producer Gazprom said earlier in June that capacity through the Nord Stream 1 pipeline, sending gas directly from Russia to Germany would be cut to just 40% due to the delayed return of equipment being serviced by Germany's Siemens Energy in Canada.

European leaders such as German Chancellor Olaf Scholz have questioned whether the cut in supply is politically motivated rather than a technical issue.

Nord Stream will also undergo regular annual maintenance from July 11 to July 21, sparking concerns about whether flows will restart when maintenance ends.

Traders said fears that an earthquake in Algeria could impact the countries exports of liquefied natural gas (LNG) exports was also bullish for European gas prices.

France said on Monday it is working on energy contingency plans because of cuts to gas flows from Russia, but it has not yet had to put them into action.

Flows via Nord Stream 1 and deliveries through Ukraine remained steady on Monday morning, operator data showed.

Eastbound gas flows resumed via the Yamal-Europe pipeline to Poland from Germany over the weekend, data from the Gascade pipeline operator showed.

The British within-day contract fell by 16.5 pence to 153.50 pence per therm, while the day-ahead contract was 1.5 pence lower at 145.50 p/therm.

“Fundamental drivers are bearish for DA (day-ahead) … This includes our forecast for lower gas-for-power,” analysts at Refinitiv said in a daily research note.

In the European carbon market, the benchmark contract edged up by 0.26 euro to 83.69 euros a tonne.

(Reporting By Susanna Twidale; editing by Nina Chestney)