A group of peers has warned that areas such as northern Scotland must not lose investment as a result of the £50billion HS2 rail project.
In a new report which raises doubts about the controversial scheme, the UK Government has been urged to ensure the East Coast Mainline to Aberdeen is upgraded if HS2 proceeds.
Concerns were raised in 2013 after it emerged in a secret report that the economy in Aberdeen, Aberdeenshire and Moray stood to lose up to £225million a year because of firms moving closer to the high-speed lines.
Business groups such as the Aberdeen and Grampian Chamber of Commerce gave evidence to the House of Lords economic affairs committee as part of its inquiry into HS2.
The north-east organisation said most companies would welcome the project, but steps must be taken to ensure the region does not lose out.
In its recommendations, the peers said: “HS2 must not lead to a reduction in investment in improving other areas of the UK rail network.
“Investment on lines such as the East Coast Mainline north of Leeds, or rail services elsewhere in the country, could play an important role in stimulating growth outside the south-east.
“Any reduction as a result of HS2 could mean these areas lose out.”
The first phase of HS2, from London to Birmingham, is due to open in 2026, with a second Y-shaped phase to Manchester and Leeds due for completion around 2032/33, although this date might be brought forward.
A third phase to Glasgow and Edinburgh has also been pencilled in, but no firm dates have been announced.
The committee concluded that the government had yet to make a convincing case for HS2.
Lord Hollick, the group’s chairman, said: “At £50 billion HS2 will be one of the most expensive infrastructure projects ever undertaken in the UK but the government have not yet made a convincing case for why it is necessary.
“The committee are supportive of investment in rail infrastructure, but are not convinced that HS2 as currently proposed is the best way to deliver that investment.”
He added: “London is likely to be the main beneficiary from HS2”.
A Department for Transport spokesman said: “The case for HS2 is crystal clear.
“It will have a transformational effect, supporting growth in the north by improving connectivity, freeing up space on our crowded rail network, promoting regeneration, boosting local skills, generating tens of thousands of jobs and helping secure the UK’s future prosperity.”