Kate and William
Could the birth of the new princess impact on the general election result? Getty

The birth of the new princess as an occasion for joy within the royal family. But could it also have an impact on next week's general election result? There is a wide variety of key factors to take into account here. Prominent among them are the impact of previous royal births on the polls, the impact of the media coverage of the birth and the opinions of bookmakers.

Conservatives will be hoping that the resultant national "feel good" factor might boost their share of the vote. At least one firm of bookmakers is saying that more of the population might now think the Conservatives will win – and it follows that this change in expectations will impact on the final result.

Unibet says that we could see more money bet on the Conservative following the royal birth, an event the firm says which normally gives a feel-good boost to incumbent parties, in line with conventional wisdom.

The firm says that bookies are the best barometers of public opinion. According to Unibet's Ed Nicholson, who has been one of the UK's leading election bookmakers over the past five elections: "Pollsters ask for opinions of a select sample of a few thousand people, but there are no real consequences of people changing their mind. Laying a bet requires the punter to really put their money where their mouth is."

But it is instructive to look at the effects on the polls of the birth of Prince George in July 2013. At that point YouGov's polls showed Labour in the lead. The Conservatives did not surge ahead; in fact Labour's lead increased by several percentage points.

Another, less obvious consequence of the royal birth is that it will favour none of the political parties. Media coverage of the birth is pushing out some of the coverage of the election during the vital final week before polling day, reducing the scope for politicians to change voters' minds.

This means that the current rankings of the competing parties could be less subject to change over the next few days. With opinion polls placing Labour and the Tories neck-and-neck, with neither party significantly likely to surge ahead, the final result could be even more nail-biting than it might have been in the absence of the Windsor's happy event.