Rail passengers have been promised a better and more efficient service under the biggest shake-up in decades.
A new state-owned body, Great British Railways (GBR), will set timetables and prices, sell tickets in England and manage rail infrastructure.
Transport Secretary Grant Shapps said it would replace an "overcomplicated and fragmented" system.
He told the BBC the changes did not mean fares would inevitably rise, but could not give guarantees.
Asked on Today if the changes meant rising ticket prices, Mr Shapps said: "No, is the answer". But he added: "I'm not here to give guarantees for years to come."
Labour said there was "little substance" behind the plans.
What benefits could consumers see?
The government says a more unified rail system will lead to more "high-quality, consistent services" from 2023 onwards, plus better connections.
There will also be changes to make travel smoother, including:
- Simplifying the purchase of tickets, which critics have long-complained is confusing
- There will be a "significant rollout" of more pay as you go, contactless and digital ticketing on smartphones
- A single, more straightforward compensation system
- And from next month flexible season tickets will be available for some people who commute two or three times a week.
The flexible season tickets will offer savings on certain routes for people who do not travel to work every day, reflecting the expected changes to commuting patterns after the pandemic.
They are due to go on sale on 21 June for use seven days later, and will allow passengers to travel on any eight days in a 28-day period.
What do passengers think?
Darshita Rajani, who lives in Wellingborough but works in London, welcomes the idea of a flexible season ticket.
Currently a season ticket for her journey costs just under £8,000. But she will only be doing three days a week when she goes back to the office so that would be prohibitively expensive.
"If things don't change I will still have to buy a season ticket, which is a waste of money, but a day ticket costs £116," she tells the BBC.
"It's insane how much they charge for a 50-minute train journey. I hope there will be two-days-a-week, three-days-a-week flexi tickets."
What is behind the shake-up?
The reforms follow the chaotic introduction of new timetables in May 2018 and years of complaints about the "fragmented" franchising system, which has been scrapped.
GBR will replace the current track operator, Network Rail, in 2023 and the government says the new system will look more like Transport for London, with multiple operators under one brand.
The systems will differ slightly in Scotland and Wales, where transport is devolved, but GBR will still operate in those nations.
The Department for Transport said in Scotland and Wales will continue to exercise their current powers and be accountable for them, but the government will explore options to ensure all nations benefit from the reforms.
GBR will continue to own the infrastructure in Scotland and Wales (other than some of the South Wales Valley Lines), as Network Rail does now.
Rail in Northern Ireland is devolved and not linked to the wider UK network.
Mr Shapps said the ultimate aim was to create "one guiding mind" overseeing the UK rail system, so there was there is more accountability when things went wrong.
Most rail services will still be run by the private sector, but under new "passenger contracts" they will be expected to meet targets on punctuality and efficiency for the first time.
What do the people behind the reforms say?
Keith Williams, the former boss of British Airways who led the review into the reforms, told the BBC's Today programme: "What we've done here is listen to what customers want out of rail and react to that.
"And that really is a more reliable punctual service and better opportunities [when] buying tickets.
"There is an enormous opportunity here not only to simplify the way that people buy tickets, but also to benefit from a retail environment which gives greater flexibility in the way that fares are operated in the future."
Mr Shapps, who also worked on the review, said the the new reforms would give the railways "solid and stable foundations for the future" after "years of fragmentation, confusion and over-complication."
On possible fare rises, he pointed out that the taxpayer had plugged a £12bn hole during the coronavirus crisis to keep the railways operating and fares were subsidised.
But he said there was no "hidden agenda".
"Of course any government in the future will have to weigh those things up," he said.
Will it work?
If the plan is followed through and properly implemented, it should see an end to the squabbling over who is to blame when the trains are late, dirty or overcrowded. Everything will be the problem of a single body.
That concentration of power will also be a potential Achilles' heel. One of the successes of the privatisation was the freedom for train companies to do new things - a freedom that was a partial factor in the remarkable revival in passenger numbers in the past two decades.
If that spirit of innovation is lost - and if civil servants and politicians endlessly interfere in the working of the new authority - the railways risk sliding into stagnation.
The fear among railway executives is that the Treasury, having had to pay dearly to support services during the pandemic, will seek to claw back spending, leading to cuts in services.
What do others say?
Anthony Smith, chief executive of passenger watchdog Transport Focus, said passengers would welcome a move "towards a more accountable and joined-up railway".
"Ultimately what they will care about is whether rail is the best option for them, if it is reliable, efficient and good value," he said.
But Labour's shadow transport secretary, Jim McMahon, said the the reforms were unlikely to work.
"With fare hikes, £1bn cuts to Network Rail and broken promises to communities across the country, it's yet another example of ministers talking a good game, with very little substance underneath."
Henri Murison, director of the Northern Powerhouse Partnership, welcomed the plan in principle saying the old franchise model "was broken".
But he called for more to be done on lowering fares in the North.
"Although more pay-as-you-go ticketing is welcome, the lack of greater progress in fares reform means that there is less incentive for people to stop using their cars to travel around the North."
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Meanwhile, the Rail Delivery Group, which represents train operators, said the proposals could deliver "the biggest changes in a generation".
Director general Andy Bagnall said: "Train operators called for a guiding mind and Great British Railways will help to bring the whole industry together.
"To deliver for passengers and freight customers, it must have the independence to hold the operators of both tracks and trains to account equally. Crucially, it needs to allow operators to put their customers at the absolute forefront of decision-making," he added.
The publication of the plan comes eight months after the government scrapped the system of rail franchising, which had been in force since privatisation, and unveiled plans to extend support for train firms.
After a drop in passenger numbers during the pandemic as more people worked from home, taxpayer money was used to plug the shortfall in ticket revenues.