Unions and campaigners are staging a protest outside Network Rail (NR) headquarters today to mark the day the company is effectively recognised as a nationalised public body by the Government.
Following a ruling by the Office for National Statistics, NR's net debt, currently £33 billion, today officially comes on to the Government's books and is included in the national debt.
This means that the not-for-dividend company, which has no shareholders and with its board held to account by members, becomes a public sector company to all intents and purposes.
Rail unions see this change as an important moment in their campaign for the renationalisation of the country's railways, arguing that as the railways are a public service, reliant on public funding, they should be under public ownership.
Mick Cash, acting general secretary of the RMT transport union, said; "The recognition of NR as a fully-fledged public body, under public control and ownership, should be seen as the spring-board for taking the entire rail network back into the public fold.
"Any attempt by the right to use this as an opportunity to argue for dragging us back to the lethal days of privatised rail infrastructure under (NR's predecessor company) Railtrack will be fiercely resisted."
Transport union TSSA said the demonstration would highlight the "contempt" the Government was showing to millions of rail passengers by its decision to exclude NR from being covered by the Freedom of Information Act.
TSSA general secretary Manuel Cortes has written to Transport Secretary Patrick McLoughlin, describing the decision as "bizarre".
He added: "Passengers pay the highest fares in Europe. They have a right to know where and how their billions are being spent."
Mick Whelan, general secretary of train drivers' union Aslef, said: "W e're delighted that NR has been brought back on to the books as a public body.
"We have consistently called for Britain's railways to be brought back into public ownership so we think it's great that half of our railway system - the steel if not the wheels - have now been brought back into public ownership."
The reclassification of NR will see the Secretary of State for Transport - currently Mr McLoughlin - having powers over the appointment of the company's chairman, its remuneration policy and the selection of its members.
The level of NR bonuses has been a contentious issue for some time, with previous transport secretaries questioning the amounts received by the company's executive directors at a time when rail regulators have criticised the company's punctuality record.
NR's remuneration committee has now restricted top bosses to annual, performance-related bonuses of no more than 20% of salary, although this could still entitle chief executive Mark Carne, on a salary of £675,000 a year, to a bonus of as much as £135,000.
A Department for Transport spokesman said: "The classification of NR is an independent statistical decision by the Office of National Statistics (ONS).
"It does not change the industry structure or affect the day-to-day operations of the rail network. The ONS decision has no effect on fares, performance, punctuality, safety or timetables."
Michael Roberts, director general of rail industry body the Rail Delivery Group, said: "NR's ability to be flexible and self-determining has enabled it to make vital decisions to maintain and invest in Britain's railway.
"The rail industry is keen to make sure that NR's operational independence is preserved while also ensuring that, at a time of record investment in the railway, the company is accountable to passengers and taxpayers. Rail passengers will see no change to the operational running of the railway as a result of this reclassification."