Transport Secretary Chris Grayling has blamed systemic failures for May's timetable disruption and has said the priority is now to "make sure this can never happen again" rather than "point fingers".

The comments came after an investigation by the Office of Rail and Road (ORR) regulator into the May timetable change concluded Network Rail, Govia Thameslink Railway (GTR), Northern, the Department for Transport and the ORR itself all made mistakes.

The inquiry's interim report warned of a "lack of clarity about roles and responsibilities." 

Mr Grayling, speaking to BBC Radio 4's Today programme, said: "I'm not going to point fingers at individuals today, it's a system problem, it's the way the whole industry works, that's what the review says."

Asked if he should take responsibility for the failure, he said: "It's tough for a politician to say to professionals in the industry to give you an assurance that something is ready and to tell them they're wrong. The priority now is to make sure this can never happen again."

Mr Grayling also ruled out nationalisation, saying "the reality is it is not about ownership, it's about the pressure on the system".

The major review of Britain's railways was launched as an investigation into what caused the May timetable disruption found "nobody took charge".

The Government said the review will be "the most significant since privatisation" and will consider all parts of the sector, including accountability, the franchising system and value for money for passengers and taxpayers.

An investigation by the Office of Rail and Road has resulted in an interim report that said: "The present industry arrangements do not support clarity of decision making: it was unclear who was responsible for what.

"Nobody took charge."

The May 20 timetable change was intended to deliver huge benefits to passengers as a result of major upgrades to the network, but instead saw services crippled in the north and south-east of England.

GTR and Northern cancelled up to 470 and 310 scheduled trains respectively each weekday during the disruption, which lasted several weeks.

The ORR stated: "The impact of this experience has had a significant financial and emotional cost to those passengers affected, directly impacting upon their work and families and in some circumstances their personal safety."

The regulator's 183-page report catalogued failures by various organisations which led to this outcome.

They included:

- Delays with Network Rail's electrification work in the North;

- Network Rail's unit responsible for producing timetables did not have a sufficient method of working to manage the scale of changes required;

- GTR and Northern were not "properly aware or prepared" for the problems with the new timetables and did not do enough to provide accurate information to passengers when disruption occurred;

- The DfT and ORR failed to sufficiently examine the assurances they received from the industry about the risk of disruption.

Events and decisions taken before January meant it was "probably unavoidable" that the launch would fail, according to the report. If there was a final go/no-go decision point it was in autumn 2017.

ORR chairman Professor Stephen Glaister, who led the inquiry, said: "Good intentions and over-optimism within the rail industry about its ability to recover missed deadlines left no time to uncover and fix problems.

"When problems arose, timetable planners were stretched and train operators were ill-equipped to help passengers."

The rail review commissioned by the Government will be led by Keith Williams - deputy chairman of John Lewis and former chief executive of British Airways - who will be supported by an external panel.

A White Paper will be published next year after Mr Williams publishes his report. Reforms are expected to be implemented from 2020.

He said the industry is facing "significant challenges".

Punctuality is at a 12-year low and commuters face an increase of up to 3.2% in the cost of season tickets from January.

There is also scepticism over the franchising system following the failure of Virgin Trains East Coast.

These issues have fuelled calls for the entire network to be taken into public ownership.

Mr Grayling will hope the rail review will reduce calls to stop private firms running services.

He accepted that the railway "needs reform to prioritise its passengers" and noted plans for closer partnerships between track and train operators on the East Coast and South Eastern routes.

He went on: "We need to go further and more quickly, to get the best from the public and private sectors, and deliver the railway we need for the 21st century.

"It is vital that this review leaves no stone unturned and makes bold recommendations for the future."

Barry White, Chief Executive of Transport for the North, said: “The interim findings of this Glaister Review clearly highlight that there is a real need for radical change in the way the rail industry operates. Fundamentally, as our members have said from the outset, changes are needed so we can be sure passenger’s interests are put front and centre of every decision made.”

He added: “The Report’s summary highlights the Rail Delivery Group’s statement that ‘the timetable is our promise to passengers’. This summer, in the North of England, and elsewhere, that promise was broken. That is unacceptable. It was passengers who suffered and that must not be allowed to happen again.”

Transport for the North’s members recently called on Government to appoint an independent person to oversee the co-ordination of the rail industry as an urgent measure to ensure co-ordination across the industry and between track and train. The appointment of Richard George, who managed the transport for the London Olympics, was announced by Government earlier this month. Members also pressed for a comprehensive compensation package for travellers and areas that have faced the worst of the disruption; schemes to provide this are currently under roll-out.

Barry White said: “That appointment, and the compensation packages, are first steps on a long journey of rail reform. The findings of this Report when it is concluded, informed by the findings of our own Review now underway through the Rail North Partnership, will help further ensure that passenger’s voices are heard.”

White said he recognised that people don’t want to hear about endless reviews, but want action, and added: “Throughout this Summer we have worked tirelessly to ensure the train operating companies stabilise services in the North and with some success – and we will continue to do so. What passengers need above all is a reliable train service, one they can depend on – and that’s where our immediate focus has been.”

The Transport for the North Chief Executive said the pan-northern organisation, which gained statutory status in April of this year, would continue to actively participate in the Review and make sure its members views were fully represented as the industry and those that regulate it move forward.