Transport Secretary to defy critics of £42billion HS2 rail link as bill begins passage through Parliament 'Paving' bill for controversial high-speed train line green-lit last week Protestors from throughout UK will descend on Parliament tomorrow Supporters say scheme is vital for economy and infrastructure Opponents of the £50 billion HS2 high-speed rail project are to demonstrate in Westminster as an HS2 Hybrid Bill begins its passage through Parliament. The protest tomorrow is being organised by the Stop HS2 group with demonstrators expected to come from as far away at Cheshire and Yorkshire. Transport Secretary Patrick McLoughlin will give evidence before the House of Commons Transport Committee on Tuesday, as will chiefs at auditing firm KPMG, which has claimed HS2 would boost the economy by £15billion a year. However, transport economists told the committee they disagreed with the £15billion prediction, with one saying the key calculation behind the figure was 'essentially made up'. Prime Minister David Cameron received a declaration of support for HS2 from leaders and representatives of the UK's ten largest cities outside of London a few days ago. Supporters hope to see a new high-speed line running from London to Birmingham by 2026 A 'paving' bill - officially called the High Speed (Preparation) Bill - received royal assent last week and has kick-started the legislation that supporters hope will see a new high-speed line running through Tory heartlands in the Chilterns from London to Birmingham by 2026. A second phase, taking the line to north west and north east England, is due for completion in 2032/33. The cost of the project is now put at £42.6billion with a further £7.5billion for the trains. Ahead of the Westminster protest, Stop HS2 campaign manager Joe Rukin said: 'With the widespread criticism of HS2 from independent bodies, it is quite depressing that MPs and Lords speaking for the project recently are so ill-informed and unwilling to listen to the exceptionally sound arguments which make it clear HS2 should not go ahead. 'On Monday, people from up and down the HS2 route will descend on to Parliament, not to say they don't want HS2 to come near their homes, but to say that they have studied the plans and justifications for HS2 and that it should be scrapped completely. It is sad that people in affected communities know more about HS2 than the majority of Parliamentarians know about what HS2 means, and we hope to change that. Opposition to HS2 has been vociferous and transport experts and economists have poured doubt on its forecasted economic benefit Mick Whelan, general secretary of train drivers' union Aslef, has welcomed publication of the Hybrid Bill. He said: 'We believe Britain needs not only a new high speed rail line but a high speed rail network. We would, ideally, like to see HS2 run the length of the United Kingdom, being built from Scotland and the south at the same time, meeting in the middle, linking HS1 (the Channel Tunnel high-speed link) and going via Heathrow. The number of passengers on our railways has doubled since 1995 while rail freight traffic has risen by 65 per cent over the same period. The House of Commons Transport Committee will be taking evidence from Transport Secretary Patrick McLoughlin on Tuesday The existing rail network is operating at near full capacity and neither new motorways nor domestic air travel are environmentally sustainable options to meet the mobility requirements of a British population expected to grow by 10 million by 2033. Last week a report by a business group in Camden in north London claimed HS2 would mean big job and economic losses in an area which boasts some of London's top markets. This was refuted by HS2 Ltd. Today Camden council said: 'As a council we are opposed to the specific HS2 proposals because of the damage the scheme would do to our community in lost jobs, demolished or heavily impacted houses, threatened schools, shut down businesses. There is simply no business case for the HS1/HS2 link up, but it would cause substantial damage to the Camden Town area. The merits of HS2 have been debated amid more antagonism and vitriol than those with long associations with transport projects can remember. Labour, although appearing to be cooling towards the project amid concerns at its high cost, seem to be supporting it in Parliament even though former Labour cabinet ministers Lord Mandelson and Alistair Darling have expressed reservations. HS2 Ltd spokesman Ben Ruse said: 'HS2 is the country's largest ever project. As such it warrants debate. However we must be clear that HS2 will yield hugely significant benefits while addressing the cripplingly strained transport network. Those that oppose HS2 are risking the very future of the country. An HS2 proposed train design. Supporters say the scheme will revitalise the UK transport system