The Conservatives have admitted their decision to divide the track and train components of the rail network in 1996 was a mistake which increased costs.
The review will lead to a strategy paper next year
Shadow transport secretary Chris Grayling told a meeting of rail industry figures there was a lack of clarity about who was in charge.
The Conservatives did not want a return to a British Rail structure but wanted more integration, he said.
Rail Minister Derek Twigg said they had not learnt from their old mistakes.
Railtrack, the company which used to be in charge of the network of train tracks, was wound up in 2001. It was replaced by Network Rail.
Mr Grayling says new thinking is needed because passenger numbers will increase by 40% in the next seven years.
He told BBC Radio 4: "There is no serious plan for additional capacity, for more trains in which those passengers can travel.
"The only people who are seriously talking about it are Network Rail who want £7 billion extra of taxpayers' money, on top of the huge amounts of money they are already receiving from government. I think we have to do things differently."
In his speech, Mr Grayling said the Tories did not intend to take Network Rail back into private ownership.
Instead, the policy would mean integrated organisations working under shorter franchise deals rather than owning the track.
The Conservatives are starting a review, which will result in a strategy paper next year.
"We think, with hindsight, that the complete separation of track and train into separate businesses at the time of privatisation was not right for our railways," he said.
"We think that the separation has helped push up the cost of running the railways - and hence fares - and is now slowing decisions about capacity improvements.
"Too many people and organisations are now involved in getting things done - so nothing happens.
"As a result, the industry lacks clarity about who is in charge and accountable for decisions."
Mr Grayling also outlined plans to give rail workers a share in the financial successes of their industry in a bid to stave off more strike action.
He said: "We know how frustrating it can be to the travelling public to see regular threats of strike action used by unions as a negotiating tactic in their discussions with their employers.
"We regard the people who work on our railways as skilled professionals, responsible for the safety, operation, logistics and customer service of our network."
Rail Minister Derek Twigg dismissed the Conservative policy as "incoherent".
"The Tories have finally admitted that their rail privatisation was a mistake but they have learned nothing from it," he said.
"Driven by dogma in the 1990s John Major's Tories fragmented our railways and driven by the same dogma in the 21st century David Cameron's Tories appear to want to fragment them again."
The plans also came under fire from Liberal Democrat rail spokesman Alistair Carmichael.
"The Tories don't seem to have learnt anything from their past mistakes, this is merely a re-privatisation by the backdoor," he said.
"These proposals are muddled in thinking and would be muddled in implementation. Because in most areas several companies share the track, this policy would lead to more conflicts between operators."