When will the election be? It’s the question that is asked whenever MPs meet. Over the Christmas recess, the issue has once again been driven up the news agenda. The reason? The announcement from the Chancellor that the Spring budget is due to take place March 6. Given this is the earliest the annual fiscal event has been scheduled for since the Tories entered government in 2010, it has added to talk that Rishi Sunak could opt for a spring election rather than waiting until the autumn. As shadow cabinet minister Emily Thornberry put it this morning, a May election is ‘the worst kept secret in Westminster’.

Sunak confirmed this month at the Christmas drinks reception with the lobby that the election will be in 2024 – rather than January 2025 (the last possible date). The general Westminster consensus has been for some time that the autumn is the most likely date: the thinking being that Sunak hasn’t had much time as prime minister so he won’t want to cut it shorter. What’s more, waiting until the autumn could allow for better economic news.

But as I first reported at the beginning of the year, there have always been figures in No. 10 sympathetic to going to the polls in May. Initially, this was based on the hope that the Tories would slowly chip away at the Labour lead and be in a better place by the spring than when Sunak took over. Going on 2 May – when the local elections are scheduled – could also help the Tories get out their vote.

Now the argument for spring reads a little differently. Those who see it as the best option do so more on the grounds that they think there is a real risk things get worse for Sunak politically after May – so going then is the least worst option. If Sunak suffers a bad result in the locals (last taken at a Boris Johnson high point) the Tory right could grow more critical and the whole party more unruly. But for every May enthusiast there are louder voices who see going early when Labour are so far ahead (around 20 points) as madness that simply goes against the rules of political gravity. It means more MPs than not still think it will be an autumn election.

As things stand, the truth is no decision has been made. Instead what No. 10 wants is to have – as senior figures put it – ‘maximum flexibility’. The spring Budget date gives them that, keeping Sunak’s options open. But he does need to tread with caution. If the government allows spring election talk to build only to choose to wait, it will deliver Labour an easy attack line – that Sunak has lost his nerve and is scared of the voters. It’s why Sunak would be wise to decide which way to go before speculation grows out of No. 10’s control.