Labour has not given up on high speed rail but wants to ensure that "costs are kept in check", a source from the party has told Associated Press.
"What we have always said is that we have got to manage these costs properly, we can't let these costs spiral out of control," said the source.
"What we need to look at is how those costs have got out of control and whether it is the best way to spend £50 billion."
"We have been pretty clear and consistent that we support the principle of a North-South rail link," he said. "There is backing for the project, but not backing for this project without regard for cost or with a blank cheque."
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Ed Balls has given his strongest hint yet that Labour are preparing to ditch its support for the controversial high speed 2 line.