HS2 high speed rail project: Martin Tett and Lord Adonis
10 January 2012 Last updated at 15:49 GMT
Martin Tett, the leader of Buckinghamshire County Council, claimed the HS2 rail scheme has a "fundamentally-flawed business case", as he was asked if a legal case was being prepared against the government.
But former transport secretary Lord Adonis said a new line was needed despite the £10bn upgrade on the West Coast Mainline, and performing "open heart surgery on a Victorian railway" would not solve capacity problems on the existing network.
Venture capitalist Jon Moulton was not impressed and claimed the figures did not support the HS2 project, initially running from London Euston to Birmingham.