Balfour Beatty has been named preferred bidder for a five-year, £90m line maintenance contract by Network Rail, the railway authority.
The work, due to start in April, will be carried out by Balfour Beatty Rail Infrastructure Services in partnership with the track maintenance company Jarvis.

The contracts are to renew stretches of track in Anglia and the southern regions, and to renovate track switches and crossings at junctions in London North-Eastern, Anglia, Scotland and the South.

Balfour Beatty, which has worked on the West Coast Main Line and the Channel Tunnel Rail Link, has an option to extend the contract by five years.

The inclusion of Jarvis as joint venture partner has led to criticism from union officials and the families of the victims of the Potters Bar rail crash. Seven people died in the crash on 10 May last year when a West Anglia Great Northern train derailed at a set of points south of Potters Bar station in Hertfordshire.

Bob Crow, general secretary of the Rail Maritime and Transport union, said the reappointment of Jarvis was "astonishing and disgusting". He added: "It is an insult to those who died or were injured at Potters Bar."

Infrastructure provider Peterhouse has also been appointed by Network Rail as preferred bidder for a £250m five-year track renewal contract in Scotland and the North-west. The contract will start in April.