Ed Balls will express his commitment to HS2 today, but will reiterate that Labour's support for the project is "not at any cost".
He is expected to tell the annual Confederation of British Industry conference today: "Labour supports HS2 and the idea of a new North-South rail link because of capacity constraints on the existing rail network. But our support for it is not at any cost.
"The Labour Party cannot - and will not - give the government a blank cheque."
More top news
Ukip and Vote.Leave have both backed Grassroots Out to become the main eurosceptic campaign for EU referendum.
Liverpool supporters groups have told ITV News they will target club sponsors next in the ongoing row over ticket prices.
David Cameron's aunt urges her nephew to provide funds to keep children's centres in his constituency open in an interview with ITV News.