The Government is attempting to convince rail passengers and transport unions that a shake-up of railway costs will drive fares down, not up.

In a Commons announcement, Transport Secretary Philip Hammond will outline the Government's response to a Whitehall-commissioned review on rail value for money being published on Thursday from former Civil Aviation Authority chairman Sir Roy McNulty.

Labour, the transport unions RMT and TSSA and the Campaign for Better Transport have expressed concerns that Government adoption of the review could lead to some fares going up.

There are also worries over an expected recommendation from Sir Roy's team that on-train staffing and ticket offices should be cut.

Rail fares for season ticket holders are already due to go up in January 2012 by 3% above the RPI inflation rate, however, the Department for Transport said the review "does not suggest raising fares by more than is currently planned".

The department added: "We're very clear that the whole purpose of the McNulty review over the medium term is to get a better deal for taxpayers and fare payers by reducing the cost of our railways. Getting the greater efficiency and higher productivity Sir Roy wants will have a downward impact on fares, not push them up."

The review is expected to say that UK rail staff wages are higher and productivity lower than in some European countries.

The RMT warned that "slashing rail funding will mean passengers pay higher fares for travelling on creaking, overcrowded trains on unsafe tracks", while the TSSA said off-peak fares could increase by 30%, and rail customer watchdog Passenger Focus said any changes to the structure of the railways had to focus on the passenger priorities of "an affordable, punctual and frequent" system.

Mr Hammond is likely to go along with the McNulty recommendation that a Rail Delivery Group should be set up which would take over some of the functions of rail infrastructure company Network Rail (NR).

The review has found that rail costs in Britain should be 20-30% lower and that costs need to be reduced by up to 35% to match some European countries. Barriers to efficiency include the fragmentation of the railways, with train companies running services but NR responsible for track and stations, and extensive government involvement in the rail industry, it said.