The Government has reaffirmed its intention to electrify the railway line into Sheffield to make way for HS2 trains - despite cuts to work on the route and fears of a new 'funding gap'.
Plans to modernise the Midland Main Line, which runs to Sheffield station, were dropped last week amid claims that 'bi-mode trains', which can run on diesel or electric power, could be used on conventional services instead.
The move came after the rail route's path through South Yorkshire was confirmed. High-speed services - electric trains - will run along tracks that follow the M1 and M18, with a spur into Sheffield city centre, starting in 2033.
The Department for Transport said the option made a saving of £858 million over the previous route, which envisaged a new station beside Meadowhall shopping centre - however, this figure did not take into account the nccessary cost of electrifying the main line between Clay Cross and Sheffield, or the bill for wiring up the railway heading north, allowing for a direct connection to Leeds.
Chris Bell, of Sheffield's Don Valley Railway group, which campaigns to introduce services between Stocksbridge and the old Sheffield Victoria Station, said: "It seems unclear whether funding has been allocated at all. It's something that's not included in the figure, but HS2 have based their decision on the cost.
"It's going to save less than £800 million when there's the cost of electrifying the line into Sheffield."
Mr Bell said the additional expense of modernising the line to Sheffield could reach £300 million, 'in consideration of the terrain'.
"At the moment it appears that funding may have fallen between the cracks."
But a department spokesman said: "The parts of the Midland Main Line that are necessary to operate HS2 services between London and Sheffield will be electrified before 2033."
A Sheffield Council spokeswoman added that HS2 Ltd had been 'clear' that electrification of the spur would be included in the high-speed programme.
On Tuesday the council's leader, Julie Dore, backed a joint statement supported by political chiefs in Manchester, Liverpool, Leeds and Newcastle that raised concerns about the future of the 'Northern Powerhouse' project, after Transport Secretary Chris Grayling threw his weight behind a new £30 billion Crossrail 2 scheme in London and the south-east.
The statement said the announcements had created 'considerable uncertainty' and urged the Government to 'correct long-term imbalances in transport funding'.
A summit for northern political and business leaders is set to take place in late August, before the return of Parliament.