The price of oil has fallen to $57 a barrel (£36/Bbl) today, according to npower’s daily market report.

Tim Carter from npower’s optimisation desk said: “That’s down from opening levels yesterday by around 5%.”

This is partially due to the outcome of the Greek referendum weakening the euro.

The gas system is forecast to close roughly balanced with the linepack 2.7mcm short.

Norwegian flows are still down as maintenance continues at Troll gas field.

The power margins are “a little tight today” at 11GW despite decent wind generation currently providing 2.5GW – however it is set to climb to more than 4GW by this afternoon.

On the latest Greece developments Mr Carter said: “The European Central Bank last night announced they would not extend the emergency liquidity assistance.

“Greek banks are shut until at least Thursday and ATM withdrawals are limited to just €20 (£14) per person per day.

“Eurozone leaders are having an emergency summit in Brussels today to discuss the situation with Germany and France.

“[They are] urging [Greek Prime Minister] Alexis Tsipras to make precise proposals following the ‘no’ vote in Sunday’s referendum.”

Mr Carter advised to “keep an eye on any Greek developments and oil prices today for UK energy price direction”.