The InterGen project would generate a total of 2.1 gigawatts of capacity at the sites in Spalding and Coryton and sustain around 3,000 jobs during construction.

The new plants together will cost up to £1bn to construct, and will be the first UK plants to use Siemens’ latest H-class gas turbines.

Under the deal Siemens will build and maintain the two power plants. Both projects have been approved and are awaiting news of whether they will obtain a UK Guarantee to help seal the financing arrangement.

A construction start is pencilled for 2015.

Mark Somerset, who heads up InterGen’s European business, added: “These are great sites, and the combination of the Siemens offer, low cost access to the networks and proximity to existing InterGen plant will make these plants ultra-competitive.

“With a firm offer from such a world-class company as Siemens, InterGen stands ready to deliver energy for the UK provided Government delivers electricity market reform which attracts investment and gives our customers and ourselves the confidence we each need.”