The HS2 high-speed rail line is unnecessary because in 20 years' time people might be able to appear at meetings as holograms rather than needing to travel in person, Ed Miliband's new business ambassador has said.
Lord Mitchell said that at first he "enthusiastically" supported the £42.6 billion scheme but had since changed his mind.
The Labour peer, an entrepreneur and former party spokesman in the Lords, has been appointed as Labour's business ambassador and enterprise adviser to the party's shadow business team.
His opposition to the scheme follows former business secretary Lord Mandelson this month warning HS2, which would speed up rail connections between London, Birmingham, Manchester and Leeds, could prove an "expensive mistake".
Lord Mitchell told the House of Lords: "I simply don't get the logic of spending £40 billion plus just to enable people to get from Birmingham to London 23 minutes earlier and Manchester to London 50 minutes earlier - for them then to be stuck in monster traffic jams on the Euston Road.
"I adore using the TGV in France and I have been envious of that country's achievements, but could it be a 20th century phenomena? Just for once why don't we try and project what the world will look like in 20 years time when HS2 is scheduled to be completed?"
He said that 20 years ago, no-one would have predicted Skype or "thought it would be possible to watch and speak to one's children in Australia holding a small device in one's hand".
He added: "Now let's project forward. In 2033 can we imagine a technology which could transmit a perfect hologram of a person half way around the world sitting on a chair in front of us? If this and thousands of other technologies that are bubbling away come to pass, who in their right mind would journey to a business meeting starting early in the day and getting home late at night?"
For the Government, Lord Newby said he had spent quite a bit of time in Birmingham over the past 20 years involved in two projects. "There is no way I could have done that without actually being there engaging people face to face," he said replying to a debate on the Government's role in generating economic prosperity.
"While I am sure a hologram of myself in front of Birmingham City Council or a head teacher would have been mightily impressive, I simply don't believe that at any point in the foreseeable future we are going to do without transport."