With the annual TUC conference in full swing, opinion among political commentators on how much power is invested in modern-day unions is polarised. Peter Riddell, writing for The Times, casts unions as a depleted force, wearily reciting threats to withdraw Labour's funds, but prevented from actually doing so by a reluctance to increase the chances of encumbering themselves with a Conservative government at the next election.

In contrast Iain Dale, emphasising the importance of the 40% of trade union members that contributed to Margaret Thatcher’s 1979 election win, asserts that David Cameron must gain favour among trade union members if he is to win the next election.

Indeed unions remain a highly influential force. Approximately 80% of Labour’s donations are provided by trade unions - an arrangement lent particular pertinence by the fact that, with its £25m debt, any cut in union payment could drive the party into bankruptcy. However, trade union influence does not only stem from financial power, but also from the sheer scale of the group represented. Six million people work in the public sector – a sizable proportion of the overall 29 million working population - three in five of whom are unionised. This group have considerable electoral sway, coupled with the potential to cause disruption through local strikes and protests – muscles which might soon be exercised with regard to the railways and postal service. Peter Riddell is too hasty in his dismissal of such organisations as unworthy of consideration as significant threats, or valuable allies. It will be important for Brown, and indeed Cameron, to continue to engage with trade unions as the election approaches.