The US presidential election remains on a knife-edge 45 days before voters go to the polls, despite Kamala Harris enjoying one of her most encouraging spells of opinion polling since becoming the Democrats’ nominee nearly two months ago.

During yet another momentous week that began with a suspected second assassination attempt against Donald Trump, the latest Guardian 10-day polling averages survey shows Harris increasing her lead to 2.6 points, 48.5% to 45.9%.

While still within error margins, that is an improvement of the 0.9% edge Harris held last week and a significant shift from the statistical dead heat of a fortnight ago before the candidates held their only scheduled televised debate in Philadelphia on 10 September.