And if the economy takes off well in the post-recession period, the growth figure could jump to 45 per cent, according to forecasts issued this week by the Advertising Association.
"Ad expenditure has recovered from all previous post-war recessions and we see no reason why the outcome of this one should be any different," an AA report said.
Even the AA's worst-case scenario suggests adspend will grow from £10.7 billion to £12.7 billion between now and 2012. The best case has the figure jumping from £11 billion this year to £15.9 billion over the coming decade.
The research, carried out by the World Advertising Research Center, is based on feedback from media owners and official long-term economic forecasts.
The AA acknowledges that forecasting long-term adspend trends is difficult, but warns the ad industry against exaggerated pessimism.
"Pundits predict the end of growth in main media advertising with clockwork regularity - usually at the very point when the industry is starting to recover," it said.
Andrew Brown, the AA's director-general, said: "It's very difficult to know when you're at the bottom of a slump without the benefit of hindsight."