A method of power production using a high pressure/low pressure ratio Brayton Power cycle with predominantly N2 mixed with CO2 and H2O combustion products as the working fluid is provided. The high pressure can be in the range 80 bar to 500 bar. The pressure ratio can be in the range 1.5 to 10. The natural gas fuel can be burned in a first high pressure combustor with a near stoichiometric quantity of pressurised preheated air and the net combustion gas can be mixed with a heated high pressure recycle N2+CO2+H2O stream which moderates the mixed gas temperature to the value required for the maximum inlet temperature to a first power turbine producing shaft power.