The stress tests at Paks, to be carried out with the cooperation of the plant’s management, the National Atomic Energy Office and the Hungarian Electricity Works (MVM), could be completed by the end of September, Fellegi said. “We are certain of the results,” he added. The results of the test will be published as long as it poses no threat to Hungary’s national security, he said.

The Paks plant, Hungary’s only nuclear power plant, accounted for 42.1pc of electricity generated in Hungary last year.