The leader of Kent County Council has questioned if the money being spent on building the High Speed Two rail link could be better used on helping fund transport schemes in the south east.
Cllr Paul Carter (Con) said he was concerned questions over the economic benefits of the new rail link - branded a white elephant by some - had not been adequately addressed.
The costs of the new link have soared to £72billion and an increasing number of people have questioned whether or not the money could be better spent elsewhere.
A Southeastern high-speed train through Ashford
Mr Carter said a number of infrastructure projects planned for the south east could be funded with the money, securing much-needed investment and jobs.
He cited the long-standing scheme for a Thanet Parkway station to provide better links to Manston Airport as an example.
"If you are going to spend this type of money, is there a case that you could spend it better elsewhere? How is it going to support the economy and growth? I don't think there has been a robust analysis," he said.
"High Speed One was built on the back of European infrastructure and connections. There is a need to improve infrastucture across the whole network and you could spend money on that. If you look at the problems with the south east, it is that they are not well connected."
Kent County Council leader Paul Carter
But Folkestone and Hythe MP Damian Collins said the High Speed Two project would be worth it.
"The question for High Speed Two is whether we can see the same improvements for the north and the Midlands that High Speed One brought for Kent?
"It could be a big catalyst for regeneration in these areas. The big selling point behind the Kent 'Grow for It' campaign is that we have High Speed One. It is the right thing to do.
"People from Kent will be able to travel to the north and the Midlands with massively reduced journey times."
Chancellor George Osborne said: "High Speed 2 is about changing the economic geography of this country, making sure the north and the Midlands benefit from the recovery as well."