Rail regulator Tom Winsor has hit back at a damning MPs' report calling for drastic rail reform and described it as "fundamentally flawed".
Rail regulator Tom Winsor has launched an angry attack
The Commons Transport Select Committee said Network Rail, which replaced Railtrack, and the Strategic Rail Authority should be scrapped.
It said Mr Winsor had failed in his "core" duty of regulating the network.
But he said the report's conclusions were based on errors of fact.
The committee believes both should be replaced by a single, publicly-owned railway agency.
But Mr Winsor attacked the report and said it "contains many significant errors of elementary fact on which its fundamentally flawed conclusions are then based".
He told BBC News Online: "The report also criticises the regulation of the stewardship of the national network and says it has failed.
"And yet for the last six months we have sustained and substantial improvements in network performance from Network Rail, which is set fair to come very close to meeting the demanding annual performance targets I have set for it.
"We also have the lowest ever recorded numbers of broken rails and temporary speed restrictions, and considerable improvements in track geometry (a measure of track quality).
Government policy is "fundamental failure of the railway"
Fragmentation getting worse
Industry costs increasing
Confusion and "buck-passing" prevalent between major rail bodies
Relationship between Health and Safety Executive (HSE)and rail industry "very poor"
Rail Passengers Council too low-profile
MPs "outraged" that £58m of taxpayers' money
used to prop up Connex's South Eastern franchise, which was eventually
taken over by the SRA
"These plain facts show that the committee has got its conclusions in this respect completely wrong.
"It is important that the debate about the future of the railway takes place in an objective and professional way, on the basis of real hard facts.
"This report is a grave disappointment on that score and is hardly a worthwhile contribution to the debate."
Some of the committee's strongest criticism were directed at Mr Winsor.
The report says he has "failed in his core function of effectively regulating the stewardship of the national rail network".
But Mr Winsor said: "I fundamentally disagree with that because the very complex task of regulating has proceeded at pace."
His comments come as Network Rail announced it would spend £26bn in five years to boost train punctuality to 90%.
The regulator was also described as "high-handed" and portrayed as a dictatorial figure who has overstepped his brief and effectively seized control of the industry purse-strings from the government.
But Mr Winsor said: "I have complied absolutely and to the full of my statutory remit."
The damning report, called the Future of the Railway, is the result of an inquiry into the state of the railways by the Labour-dominated committee of backbench MPs.
They found that fewer than 80% of trains arrive on time.
Latest estimates say it will be five years before performance matches British Rail's best figure of 90% of trains on time.
The SRA is described as "largely incapable" of its job of setting standards for the private train companies.
Richard Bowker, chairman of the SRA, defended the organisation's achievements, such as tackling the West Coast Mainline.
But he agreed the current structure of the industry was "overly complex".
Network Rail said it was disappointed the committee failed to recognise improvements in infrastructure, cost-cutting and the upcoming investment in railways.
The Transport Secretary Alistair Darling agreed with much of the report and said he would consider abolishing Network Rail and the Strategic Rail Authority.
He said a publicly-owned rail agency could lead to greater simplicity for commuters.
Shadow transport secretary Theresa May MP said the report showed how Labour had let