The 21-strong claimed the project, which is to run through the country via Birmingham before reaching Leeds and Manchester, will cost every family more than £1,000.
The signatories to the letter included former Chancellor Lord Lawson; Ruth Lea, former head of policy at the Institute of Directors; Chris Kelly, chairman of Keltruck; Cheryl Gillan, the Welsh Secretary and MP for Chesham and Amersham; and David Lidington, MP for Aylesbury and a Foreign Office minister.
But the transport Secretary said: “The letter did not particularly concern me. The key thing for me is that we have seen mainstream business leaders throwing in behind the project.
“Nigel Lawson doesn’t believe in climate change – neither does Ruth Lea - and Chris Kelly, who I know very well, has made his fortune importing trucks. He is hardly going to be a promoter of the railways. He thinks we should take £33bn and widen all motorways to six lanes.
“It doesn’t surprise me that people who are truck importers and climate change deniers would find the arguments less than persuasive.”
But he warned: “There are an awful lot of people who assume this is a done deal. There is a danger of some of the people who are going to benefit most from this thinking they don’t have to get out of bed and argue the case.
“The people who think that they will suffer from it will not rest and will make their case quite aggressively and probably quite effectively.”
Ironically, the transport secretary appeared to predict the furore at a conference in Manchester two weeks ago when he said: “The consultation will see opponents of high-speed rail, mainly in the South, argue their case and deploy every weapon available to them to try to stop this project.
“It is essential that those who see the power of high-speed rail to deliver economic change and benefit Britain to speak up loudly and clearly in favour of this project as the consultation progresses.
“That includes the Labour Party who were, in office, pioneering on this issue but have wobbled dramatically over the last few months in their commitment to what was clear policy.
“It includes business which has to unite behind the proposal and it includes civic leaders who have to mobilise public engagement just as civic leaders in the Chilterns are mobilising and bankrolling those who are opposed to HS2.”