Today's Institute of Economic Affairs report suggesting that the cost of High Speed 2 could reach £80bn (it was officially revised up from £30bn to £42.6bn last month) will strengthen the hand of the growing number in Labour who argue that the party should come out against the project. Peter Mandelson (who described it as an "expensive mistake") and John Prescott have both urged Ed Miliband to do so and Alistair Darling (a self-declared "HS2 sceptic") has warned that an "awful lot of things" are wrong with it.
Ed Balls, who recently remarked, "We need to keep a close eye on value for money. I am concerned about the rising costs", is sympathetic to their position. A pledge to cancel HS2 would free up billions for more electorally popular policies (such as a mass house building programme) and reduce the need for higher borrowing and tax rises. It would also split the Tories down the middle, ending what has become a sustained period of Conservative unity.
But Ed Miliband remains personally supportive of the project and HS2 evangelist Andrew Adonis, the party's shadow infrastructure minister, who Miliband recently appointed to lead a growth review, is also determined to prevent any backsliding. However, with his recent pledge to remove winter fuel payments from wealthy pensioners and to introduce an opt-in system for trade union funding, Miliband has shown that he is willing to revise long-standing positions when political conditions demand it. A promise to cancel HS2 and invest the savings in more valuable projects is just the kind of gamechanger that he needs for the conference season.