I was just asked by BBC News whether the reforms proposed by Ed Miliband to the Labour-union link could be compared to Tony Blair's rewriting of Clause IV in 1994. My response? Yes, but they're bigger.
While Blair's decision to revise Clause IV, which committed Labour to "common ownership of the means of production, distribution and exchange", was of immense symbolic significance it changed little in practice. Labour had already effectively abandoned wholesale nationalisation and no one would have expected Blair to pursue this policy as prime minister.
By contrast, the changes proposed by Miliband, most notably the introduction of an opt-in system for trade union members' donations, will have dramatic consequences for Labour. As I revealed earlier, the party estimates that it could lose as much as £5m of the £8m it currently receives in affiliation fees. The hope is that this reform will force the Tories to agree to party funding reform, including a £5,000 cap on individual donations, but it remains the biggest gamble of Miliband's leadership. It's for that reason that Blair himself was so fulsome in his praise this morning.