With its lurid predictions of recession, job losses and tumbling house prices, yesterday's Treasury report on the short-term economic impact of Brexit is a bracing read.
It has been published a month ahead of the referendum and the Remain side hopes it will consolidate its lead on the economy, the issue that polls show is most important to voters.
The message about the economic risk of leaving the EU will get a few more airings this week. Bank of England governor Mark Carney will be back before a parliamentary select committee today, ostensibly to talk about monetary policy but he is almost certain to be asked about Brexit.
And leaders of the Group of Seven industrialised countries are likely to add to the chorus of warnings when they meet in Japan later this week.
Leave campaigners blame Carney’s intervention in the debate for a shift towards Remain in recent days, acknowledging voters view the banker as an independent figure. A leading figure in the Leave campaign complained to me yesterday that the campaign has been unfair because the government can use the civil service to make its case.
That will end on Friday, when “purdah” is imposed, banning the use of officials by the Remain side. The Leave politician predicted that the campaign will change after that, as it moves from an “air war” to a “ground war”. Interventions such as yesterday’s Treasury report had allowed the Remain side to dominate the air war, he said, but he predicted that Leave’s superior ground operation of volunteers at local level would come into its own from now on.
Leave campaigners’ claims that they have not given up on the economic argument are belied by their strategy, which has shifted to an almost exclusively to immigration.
This week has seen Leave campaigners warn about the impact of Turkish accession to the EU, erroneously claiming Britain does not have a veto on any new member-state joining.
Later this week, Leave will focus on the National Health Service but here too the main argument is about the impact of immigration on the service.
Status quo
Although the headline figures in the polls point to a close race, the Remain side has a clear advantage on the most important issue, the economy, and history suggests that support shifts towards the status quo towards the end of a campaign.
The rest of the EU has not yet obliged the Leave side with a fresh crisis over migration or the economy.
An external shock could yet upend the Remain campaign but, for now, the greatest challenge for those who want Britain to remain in the EU is to avoid complacency and do everything possible to motivate their lukewarm supporters to vote on June 23rd.