The February election of 1974 saw Prime Minister Edward Heath involved in an unusual electoral battle.
Not only was he taking on Labour and the Liberals as usual, Heath was also pitting the office of prime minister against the 270,000 strong National Union of Mineworkers in a contest to see who would govern Britain.
As Heath put it himself: "To give way to wage demands which go beyond what the nation can afford and beyond the Stage 3 code would lead to a situation in which the economy would be damaged infinitely more [than the three-day week]."
It was a serious situation which the prime minister judged could be best be resolved only by having a firm mandate.
But Heathís decision to call the election was a high risk strategy. It was questioned by those in his own cabinet who pointed out he still had a reasonably healthy parliamentary majority and over 18 months to go before the end of the parliament.
The election also put Labour leader Harold Wilson in a difficult position.
With the unions causing much misery for ordinary householders he could not give the strikers his unqualified support, on the other hand the trade union movement was Labourís traditional bed rock of support whom he could not afford to offend.
Wilson had hoped the strike would be called off during the election but when it was not, he criticised the government for wasting time in attempting to deal with minersí wage claims which had first appeared in July 1973.
Rather than take the more aggressive stance adopted by Heath, Wilson attempted to take on the role of the mediator - by pointing to his "social contract" with the TUC he seemed to be offering partnership in government rather than confrontation.
All in all it was a difficult campaign for either of the main party leaders to fight - it was a situation that benefited the Liberals under Jeremy Thorpe who called for an end to politics dominated, on the one hand by the unions, and on the other by business.