With a Conservative-led coalition in power, who should lead the Labour party in opposition and how far will they depart from the New Labour brand? How should the party and the trade unions frame their response to the Government's plans for dramatic cuts in public spending? Brendan Barber is the General Secretary of the Trades Union Congress, the majority of whose members work in the public sector. On the eve of the TUC conference in Manchester, Stephen Sackur asks him whether the unions are about to flex some old Labour muscle.