This means the politicians can increase spending, but simultaneously claim they are cutting spending because the budget could have expanded at an even faster pace.
Sort of like saying your diet is successful because you’re only gaining two pounds a week rather than five pounds.
Anyhow, some people get deluded by this chicanery. Paul Krugman, for instance, complained in 2011 that “the government of Prime Minister David Cameron chose instead to move to immediate, unforced austerity, in the belief that private spending would more than make up for the government’s pullback.”
This was nonsense. There have not been any genuine budget cuts in the United Kingdom. Heck, just compare what’s happening today in the United Kingdom and what happened in Canada in the 1990s to see the difference between gimmickry and real fiscal restraint.