The cost of building the HS2 railway line is nine times higher than it would be in France, a damning report concludes today. A House of Lords committee says the £50billion project should be stopped in its tracks until ministers can make a stronger case for it. Their report – The Economics of High Speed 2 – says the Government's sums do not add up. They claim ministers have failed to consider an alternative to spending £50billion on one line, asking: 'How much could be achieved if that money were invested differently? Scroll down for video . Criticised: A House of Lords committee has called for the £50billion HS2 project (artist's representation) to be scrapped arguing that ministers have not made a good enough case for its construction . 'The cost per mile of HS2 is estimated to be up to nine times higher than the cost of constructing high speed lines in France.' The report by the economic affairs committee concludes the Government has many questions to answer on cost, benefit, reducing overcrowding and helping the regions. It adds: 'Parliament should not approve the enabling legislation that will allow HS2 work to begin until we have satisfactory answers to these key questions.' 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. The report says HS2 is supposed to rebalance the economy but it is London rather than the Midlands or the North that is likely to be the biggest beneficiary. Lord Hollick, chairman of the Lords committee, said: 'At £50billion, 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.' Joe Rukin, of the Stop HS2 Campaign, said: 'This is surely another nail in the coffin of HS2. The case for HS2 has been ripped apart again so thoroughly that cancelling the white elephant is surely now the only option.' Waste of money: The report says HS2 is supposed to rebalance the economy (graphic from 2013) but it is London rather than the Midlands or the North that is likely to be the biggest beneficiary . The report is a serious blow to Transport Secretary Patrick McLoughlin. However the Department for Transport insisted HS2 would deliver more than £2 of benefits for every £1 invested. In a statement, it 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.' On HS2's ability to relieve congestion, the peers said full information on passenger numbers had not been made available by the Government on grounds of commercial sensitivity. They said the target price for phase one of HS2 gives an average cost of around £90million per kilometre. The French TGV network cost £9.7million a kilometre.
House of Lords committee says ministers have not considered  alternative . Claim HS2 line would cost 'nine times more' in UK than it would in France . The first phase of HS2 from London to Birmingham is due to open in 2026 . The high-speed line is supposed to help balance the country's economy . Lords argue London rather than the Midlands or the North will benefit most .