According to the prequalification notice the new Overhead Lines Design and Build Framework will be worth up to £2.5bn over four years.

It is the second time NGET has invited firms to prequalify for this new framework after cancelling the process earlier this year.

Procurement bosses hope a return to traditional engineer, procure and construct deals with contractors will bring bigger savings from increased competition from specialist international firms eyeing the UK market.

The plan is to select around six consortia to bid for individual contracts over a four-year period.

NGET has stressed it aims to keep its options open on the extent of work placed through the design and build route until existing alliance agreements with its 15 contractors are due to be renewed in 2017.

In the meantime, it will carve up over-head powerline work between both procurement routes.

The move will be greeted with concern among the major contractors who are counting on a steady stream of work from NGET.

Just last year Balfour Beatty signed a five-year contact extension worth around £750m under the Electricity Alliance East partnership.

While joint venture partners Amec and Babcock took a £650m deal for the Electricity Alliance West framework.

Other major partners include a Morgan Sindall and Vinci Energies joint venture and Carillion.

Firms have been given until the 15 July to express an interest.