There won’t be one. Stop being silly.

If you’d like a longer answer. The birth of Prince George had no discernible effect upon the polls, the Royal Wedding had no discernible effect. The Diamond Jubilee was followed by a couple of polls with a reduced Labour lead, but nothing that couldn’t have been normal sample variation. Events with direct relevance to the election normally have little or no effect on voting intention; the leaders debates had minimal effect, scandals and policy announcements normally have minimal effect. The idea that something with such a complete disconnect from the things that determine voting intention will have an impact is somewhat fanciful.

The only direct impact it makes is the news agenda. If any of the parties were planning on a big policy announcement over the weekend it will now have to struggle against the royal baby to get in the papers and the news bulletins.

Of course, should the polls move in the next few days I expect history will record that the royal baby won the election for David Cameron, in the same way that we pretend that the bug in Gordon Banks’ tummy lost the 1970 election for Harold Wilson. In reality I expect any change in the polls over coming days will be noting at all to do with royal procreation, and everything to do with the existing drivers of voting intention – people making their minds up or changing their minds based on perceptions of the leaders and parties, of competence in running the economy and public services, and hopes of fears of what sort of government will emerge from a hung Parliament.