The Labour Party, and thus the British government itself, is currently massively in debt to the trade unions. Not just purely financially either.
The Daily Telegraph can disclose that the unions paid for six million direct mail shots, organised a postal vote recruitment campaign, provided teams of drivers, set up a nationwide website and sent almost 200 campaign officials to the marginal seats.
The logistical support, which was worth millions of pounds, helped galvanise trade unionists to go out and vote in May 2005. The unions boasted that the strategy made such an impact it "helped Labour win a third term". (The Telegraph)
That the trade unions can say that it is them "wot won it" for Labour in 2005 gives them a very strong hold over Labour during their third - and hopefully last - term, considering that Labour's position in the polls will just decline in the long run and as such Trade Union support may well be essential for them. That a British government is so indebted to such a small interest group is wrong, and scary, in so many ways.