The new super-union created by Amicus and the T&G, as yet unnamed, is due to be formally born on May 1 – an appropriate Labour Day event. It will be Britain’s largest union with some two million members.

Although union mergers are not uncommon (there were around 270, mainly transfers of small unions to large unions, between 1978 and 2006) amalgamations involving Britain’s larger unions are relatively rare. Unison (1993) and Amicus (2002) represent the most recent similar mergers, but each fell some 500,000 members short of the new Amicus-T&G amalgamation. Furthermore, and perhaps more importantly, this new merger will shift a significant proportion of Britain’s union membership into a single union: it will organise 30 per cent of the TUC’s total membership.

The advantages sought by the Amicus-T&G amalgamation do not, however, differ from previous large amalgamations. Externally, the central objective is to increase the partner unions’ influence over those organisations or actors which can affect the unions’ members’ terms and conditions of employment. Internally, the new merger will hope to generate opportunities for major economies of scale. As a result, broader political considerations are unlikely to be at the forefront of the new union’s agenda. More attention is likely to be focused on who is taking redundancy and who will be the next general secretary.

Nevertheless, even though the Amicus-T&G leadership is unlikely to focus most attention on its relationship with the Labour party post-merger, it is causing some new political anxieties elsewhere. In a political context much exercised by the Hayden Phillips’ report on party funding and the cash-for-honours investigation, the possibility of a single union providing a major part of the Labour party’s union donations is in danger of raising new questions over the party’s financial propriety.

In short, it is feared that the Amicus-T&G amalgamation and the associated union donation to party funds will give its leaders a disproportionate influence over the Labour party and, in consequence, government policy. Such a cash and policy nexus could obviously be damaging for the party and government.

Such associations between payment and performance are, of course, not new. Indeed, it could be argued that the pursuit of unpopular policies resulting in non-payment of individual subscriptions produced the recent marked reduction in Labour party membership. Some factors associated with the Amicus-T&G merger may be offered in support of a parallel argument that the new union will also take a more instrumental view if its party affiliation. For example, the government continues to ignore Amicus-T&G proposals for changes in its health reforms and employment rights policies, as expressed in alliance with Unison and the GMB at the 2006 party conference.

Yet, despite these areas of potential conflict, it is still highly unlikely that Amicus-T&G will attempt to use its influence in such an overt manner, or take umbrage and reduce, let alone cease, its donations to the Labour party. It is far more likely that the new union will continue to pursue its interests in the usual processes via the party structure, and direct to government via the relevant ministers and secretaries of state and the prime minister.

This twin track approach – including the use of the Trade Union and Labour Party Liaison Organisation, of which Amicus presently holds the chairmanship – should allow the new union to make its views heard without threatening to withdraw or reduce its financial contribution. This is not to say, however, that Amicus-T&G may not, in the longer term, become more instrumental in its attitude towards both party and government, particularly as some forces previously seen as helping unite the different parts of the Labour movement have weakened under New Labour.

But, in the short run, recognising that the next general election is starting to overshadow other political considerations, union leaders will not wish to damage New Labour’s chances and open the door for a Conservative government. Pragmatically, they will recognise there is no acceptable alternative to a New Labour government.