Fares on the £50 billion HS2 high-speed line must be affordable and should be "broadly comparable" to those charged on other lines, rail industry chiefs said today.
There have been concerns that premium fares will be charged for those using the new high-speed line whose first phase, from London to Birmingham, is due to open in 2026.
Passengers travelling on domestic services using HS1, the 186mph Channel Tunnel fast link, pay much higher fares than those using "conventional" Kent commuter services.
Today, rail industry body the Rail Delivery Group (RDG) said "setting fares at the right level" was one of its five key priorities for HS2.
The RDG went on: "Prices should be broadly comparable with those on other sections of the network to ensure the new services are affordable and encourage more rail travel on HS2 and across the existing railway.
"Tickets for HS2 should be sold through the same national retailing outlets as for the existing network."
HS2, fiercely supported by some and bitterly opposed by others, runs through Tory heartlands in the Chilterns on its route from London to Birmingham.
The RDG's priority list comes ahead of a report on Monday by former London Olympics supremo Sir David Higgins, who is chairman of HS2 Ltd, the organisation developing and promoting the project.
It is thought that his report will recommend scrapping the proposed link between HS2 and HS1. This could put Sir David at odds with the RDG which today listed "plugging HS2 into the existing network" as one of its priorities.
The RDG added: "The new and existing railway needs to be linked seamlessly".
The cost of the full HS2 is currently £42.6 billion, with a further £7.5 billion needed for the trains.
In his report on Monday, Sir David will outline possible savings, which could include £1.5 billion in London alone. He is also likely to call for work to start on phase two of the project at the same time as phase one.
However, Transport Secretary Patrick McLoughlin has said that the phase one legislation will not get through Parliament before next year's general election.
Also, the exact route of phase two has yet to be determined in complete detail and will need its own separate consultation and legislation.
Sir David is also likely to call for a completely new Euston station in London as part of HS2's London terminus plans.
Seen as a "heavy hitter" and a "mover and shaker" Australian-born Sir David, who has joined HS2 Ltd after being Network Rail chief executive, is also expected to call on MPs for all-party unity on the project.
Labour keenly supported HS2 when in power, with pro-rail Labour transport secretary Lord Adonis an enthusiastic fan of the project.
But shadow chancellor Ed Balls has expressed reservations about the cost of the project and among others who have now cooled to the scheme are former Labour chancellor Alistair Darling and former Labour industry secretary Lord Mandelson.
RDG general secretary Michael Roberts said today: "HS2 must become the backbone of a growing railway if we are to meet the challenge of booming demand for extra passenger and freight services that Britain faces now and in the future.
"The time has come to move on from debating if the new line is necessary, and focus on planning how services will be run, drawing on the expertise of a country with the safest and fastest growing major railway in Europe. The rail industry will work with government, HS2 Ltd, passenger groups and suppliers to help ensure the new line is a big success."
Sarah Hayward, leader of Camden Council in north London, said: "If reports of what will be said on Monday are to be believed, it seems that David Higgins recognises that the current plans for Euston are the worst of all worlds for Camden and the country.
"As it stands, the current plans are a lean-to, bolted on to a shed that offer nothing to the local community but nearly two decades of blight.
"We also hope that the report will make the recommendation to scrap the badly-thought-through and unnecessary HS1/HS2 link. It will devastate Camden Town, which is one of Europe's most popular tourist attractions and currently supports thousands of jobs."
Later, the RDG clarified that it had no particular views on any possible HS2-HS1 link but supported any links with HS2 for which a business case could be made and which were necessary and possible.
An HS2 Ltd spokesman said: "The priorities set out by the RDG highlight the vast benefits HS2 will bring to the transport network and the country as a whole.
"HS2 Ltd looks forward to working with the RDG and other industry bodies to ensure these priorities are met and the full potential of the project is realised. On Monday, Sir David will publish his report entitled HS2 Plus."
Jeremy Acklam, from the Institution of Engineering and Technology, said: "One of the biggest benefits of HS2 is the economic redevelopment opportunities.
"We've heard a lot about these opportunities for the major cities connected by the high-speed line, but little or nothing about the potential wins for cities beyond the immediate confines of the HS2 network."
He went on: "There is great potential through the connections to the East and West Coast Main Lines for cities other than Birmingham, Manchester and Leeds to benefit from HS2, but the challenges around realising these benefits need to be tackled now if these locations are not to fall behind."
A Department for Transport spokesman said: "Our assumptions on the viability of HS2 and the expected fares income do not factor in or depend on a premium for high-speed services.
"All our appraisal has been based on high-speed rail fares being in line with existing services, and we have made clear our determination to see the cost of running our railways come down so that we can deliver a better deal for both taxpayers and farepayers."