The allegation was denied by the group but the EU demanded that Hamas guarantee the power station is independently operated.
On Tuesday, Ismail Haniya, the former Palestinian prime minister and a senior Hamas leader, said the group would prove that it was not interfering in the supply of power.
"To ensure the people's right to be free of electrical power cuts, the government will give verifiable guarantees that the electricity company will work independently as mandated and without any interference from the factions," he said in a statement.
At a Hamas meeting, Haniya said the "electricity company is independent and there is no interference in its administrative affairs".
"This is part of the pressure exerted on Gaza and attempts to break our will."
Factional split
"The continuation of these power cuts are causing incommensurate harm to the life of our people, who are not guilty of the banditry by Hamas and its militias"
Mahmoud Abbas, Palestinian president |
The EU issued its statement after holding talks with the Palestinian Authority government in Ramallah and the crisis has highlighted ongoing tensions between the rival administrations in the West Bank and Gaza.
Nour Odeh, Al Jazeera's Gaza correspondent, said Palestinians, however, were not happy with anyone's performance during the five-day crisis.
"The crisis has been solved by Salam Fayyad, the Palestinian prime minister in Ramallah, and has emboldened the government there.
"It is a reminder that the European Union is only dealing with the government of president Abbas," referring to Mahmoud Abbas, the Western-backed Palestinian president.
Hamas took control of Gaza after continued clashes with Abbas's Fatah faction in June.
Hamas blamed
Abbas said his Hamas rivals were to blame for the outages as it was keeping money from electricity sales.
"The continuation of these power cuts are causing incommensurate harm to the life of our people, who are not guilty of the banditry by Hamas and its militias," he was quoted by his office as saying.
One of Abbas's first decrees after Hamas seized control of Gaza was to exempt its 1.5 million residents from paying taxes, a move designed to keep Hamas from collecting any revenues.
He said the fuel cuts were "the result of the illegal takeover of control electricity company by the Hamas putschists, and the collecting of citizens' [electricity] bills to pay members of its militia".
Hamas had denied the allegations, saying it had arrested the head of the electricity company on charges of corruption.
The EU, the US and other major Western powers have imposed a crippling economic and diplomatic boycott against Hamas over its refusal to recognise Israel, renounce violence and abide by interim peace deals.