LONDON, June 28 (Reuters) - Dutch wholesale gas prices fell on Tuesday morning, with the easing of some concerns over Russian supply as supplies remained stable, whereas British gas prices rose in response to forecasts for higher demand from electricity plants.

The benchmark Dutch wholesale gas contract for July delivery was down 3.35 euros at 126.50 euros per megawatt hour (MWh) by 0815 GMT, while the August contract fell by 5.50 euros to 126.50 euros/MWh.

Europe is "still receiving lots of gas and Turkstream pipeline resumed flows," a European gas trader said. "Bearish outlook will likely remain if no surprises show up."

Russian gas flows from Serbia into Hungary have resumed after maintenance on the Turkstream pipeline. Flows of Russian gas to Europe via the Nord Stream 1 pipeline and through Ukraine were steady early on Tuesday.

The European Union's energy chief on Monday urged countries to update contingency plans to cope with supply shocks and switch to other fuels wherever possible to conserve gas, in preparation for a possible "serious disruption" from Russia.

Russian gas producer Gazprom said earlier this month 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.

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

The British within-day contract rose by 5 pence to 150 pence per therm, while the day-ahead contract was 13 pence higher at 155 p/therm.

Refinitiv analysts said a forecast for stronger gas for electricity generation was an important bullish driver for day-ahead prices on Tuesday.

Gas for electricity is seen higher by 20 million cubic meters (mcm) at 58 mcm for the day ahead.

In the European carbon market, the benchmark contract edged down by 0.54 euro to 84.54 euros a tonne.

(Reporting By Marwa Rashad; editing by Bradley Perrett)