Full Fact confirms that the OBR forecasts the tax burden at 37.9% of GDP in 2027/28, the highest since comparable records began. It adds that those records only go back to 1948/49.
That supports Kemi Badenoch's claim of a record tax burden next year, but only within that series. In her Commons Budget reply, the Conservative leader said:
"next year under [Labour] Britain will have the highest tax burden in our country's history. Higher than the 1970s. Higher than in the Second World War. Higher than in the Napoleonic Wars."
Because the comparable series starts in 1948/49, it cannot support her comparisons with the Second World War or the Napoleonic Wars.
Full Fact says the Napoleonic Wars line may come from a point Dan Neidle made earlier this year. He said the number of individual UK taxes was the highest since the Napoleonic Wars. Full Fact notes that this is not the same measure as revenue as a share of GDP.
Full Fact has asked the Conservatives what the two wartime comparisons were based on and says it will update its article if they reply. Guido Fawkes reports that the party received Full Fact's email.