Paul Massara made the claim in a letter to energy market regulator Ofgem.
Labour leader, Ed Miliband, said almost a year ago that the party would implement a price freeze on all gas and electricity tariffs in the UK for 20 months if it won the general election in 2015.
Mr. Massara stated that reducing its energy prices now would be a risky move. Although the wholesale gas market is currently seeing lower gas prices, the supplier would not be able to raise the prices of its own tariffs in line with any market changes if Labour were to be victorious.
In his letter, which has been published in The Times, the nPower chief executive wrote: "The political and media pressures at the moment make it more difficult to reduce prices and then increase them again next spring.
"Then we are acutely aware that if the Labour party were to implement their proposed price freeze, we will be living with the consequences of our standard rate tariff price for a very long time and beyond the level of risk that we could manage in the wholesale market," he added.
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