The man in charge of Britain’s railways is under pressure in Whitehall to step down, amid frustration about the slow pace of change and criticism of his £820,000 pay package.

It is understood that the Government wants Mark Carne, the chief ­executive of Network Rail, to leave when there is a “natural break” in his contract this year.

His departure could be sealed as soon as the spring, according to Whitehall sources, with further months ­required to find and appoint a new leader to steer the railways through a crucial period of rising demand and public ­investment.

There is no formal process under way to identify successors, but ministers are understood to be keen to see Network Rail make a fresh start and accelerate ­improvements to tracks.

An insider said: “He has struggled with parts of the relationship with ­government.” It is understood that tensions have included Mr Carne’s remuneration, which is among the highest in the public sector and has provided ammunition to government critics.