Earlier this month a storm broke in the British Labour Party about its link with trade unions. It was caused by a row between the party and trade union Unite about the candidate selection process in the Falkirk byelection.

After an incident involving the bulk enlistment of members of the union in the Falkirk constituency Labour party, the local party chairman and the aspiring candidate were suspended and disputed membership applications frozen. An under-pressure Labour leader, Ed Miliband, subsequently promised to reorient the links between the party and the unions.

The nub of Miliband’s proposal is that union affiliation will in future be based not on total membership of the union, but on the number of union members who are also individual members of the Labour Party. The proposal was welcomed by Unite general secretary Len McCluskey. So all is sweetness and light – or is it?

Unions who financially support political parties are legally obliged to use a political fund for this purpose. This dates back to a 1909 British court case known as the Osborne judgment. Every union member must have the right to opt out of a political fund. This puts individual union members in a more powerful position than shareholders who have no say in how the companies they own intervene in the political process.

In Ireland, relatively few unions are affiliated to the Labour Party. But Irish unions already exercise influence in the party only in proportion to the number of party members they have in membership.

Business-funded think tanks
So what has gone wrong with the relationship between the British Labour Party and its union affiliates? The current controversy has elements of the traditional left-right battle within the British Labour Party. Unite argues that it broke no rules in Falkirk, and that the union's role in party life is less divisive than that of think tanks such as Progress, established by Peter Mandelson, a close ally of former prime minister Tony Blair, and largely funded by donations from business.

The head of the large GMB union, Paul Kenny, has called for the Progress grouping to be expelled from the party in the same way as the Trotskyite Militant Tendency was expelled in the 1980s. The union accused Progress of attempting to sabotage Labour’s London mayoral selection, and has raised questions about the group’s funding.

The Falkirk controversy is partly about the Labour-union link and partly a result of the culture of politics in the Scottish central belt. But most of it relates to single-seat constituencies.

The combination of single-seat constituencies and the first-past-the-post system creates safe seats, which can be a job for life. This applies as much in Tory shires as in the former heartlands of Scottish industry. A classic product of the culture was Neil Hamilton MP, of the “cash for questions” scandal. Safe seats weaken the grip of voters on electoral power, something that advocates of electoral reform in Ireland often overlook.

Challenging the right of unions to exercise political influence is a perennial issue in British politics. This is grotesque when you consider the huge amounts of money that enter the British political system through corporate donations. Individuals and groups will always seek to influence the political process. The public interest requires that political funding and the exercise of political influence should be as open as possible.

Voices of the marginalised
The essence of this argument is contained in an article on the Progress website: "Labour is immeasurably stronger because of the relationship it has with the unions: no other centre-left party in the world has unions formally affiliated to it. [This is wrong as it ignores the Irish case.] Not only have the unions historically ensured that the voices of some of the most marginalised in society are heard in the corridors of power, there is also strong international evidence to suggest that trade union activity plays a wider part in maintaining the health of democracy: it is, for instance, closely linked to ensuring higher voter turnout, particularly among working-class voters who might otherwise not go to the polls."

The latest controversy has arisen at a time when David Cameron is again facing difficulties over the issue of "influence peddling". As Seamus Milne wrote in the Guardian, "His election adviser, Lynton Crosby, is a lobbyist – for tobacco, alcohol, oil and gas companies – which is why the prime minister came under attack for dropping curbs on cigarette packaging and alcohol pricing. His party treasurer Peter Cruddas resigned after offering access to Cameron for a £250,000 party donation. His defence secretary, Liam Fox, resigned over his relationship with the lobbyist Adam Werritty."

This comes just two years after Andy Coulson, Downing Street’s press secretary faced criminal charges for phone hacking while he worked for the Murdoch empire.

The central aim of trade unionism is to ameliorate the unjust effects of capitalism and to liberate working people from the dehumanising and commodifying effects of markets on a wider society. The means to this end are influence at the ballot box, collective bargaining and support for the development of welfare states. Influencing the outcome at the ballot box is a legitimate act.

Unions have been attempting to influence the actions of Labour parties on these islands for over 100 years. That they should seek to do so is hardly news. The real story of Falkirk is not the internal spat within the British Labour Party, it is in the way this dispute was magnified by Tory politicians to attack union funding, described by the Guardian as "probably one of the cleanest, most transparent and accountable money in British politics".

Dr Peter Rigney is an industrial officer with the Irish Congress of Trade Unions