ITV warns advertisers are not spending money due to Brexit uncertainty

Revenues dropped as much as 16 per cent in March and are set to plummet by around 20 per cent in June (Getty)

Advertisers are cutting back on spending in the traditionally busy run-up to the holiday season because of ongoing uncertainty about the UK's future, ITV has said.

Chief executive Dame Carolyn McCall blamed an “increasingly uncertain economic environment” for a “softening” in marketing spending on its channels.

The broadcaster warned that spending would fall by an estimated 8 per cent in December, as customers rein in their spending on Christmas adverts.

Marks & Spencer and John Lewis have not launched their festive adverts yet, suggesting a more cautious outlook among retailers than in previous years as the UK prepares to leave the EU.

ITV's ad income fell by 3 per cent in October but the company predicted it would rise by 2 per cent this month,

ITV said its performance in the first nine months of the year was "very much as expected", with total advertising up 2 per cent, driven by 43 per cent growth in online revenues.

Ms McCall said: "We have an exciting schedule for the remainder of the year and into next year with entertainment shows I'm A Celebrity and Dancing On Ice, and dramas including Cheat, Cleaning Up, Manhunt and The Widow as well as the Rugby World Cup exclusively on ITV."