Casual misinformation

I watched the 9 p.m. news on GBViews last night before going to the recording of Carmageddon. Mark Dolan started waffling about a swing to Labour in the recent by-elections at the start of his programme.
    In one of the elections, my expert assures me, the Labour vote fell compared to the turnout in 2019, and just 5% of the Tory voters who didn’t bother last week returning to the fold would put both Labour place-holders back in their box.
    So where’s the swing?