While 31 per cent of retailers said sales in the first two weeks of December were lower than a year ago, 30 per cent said they were up, meaning those experiencing a good and bad month were virtually even.
The figures are a dramatic improvement on November, when a balance of 35 per cent of retailers had experienced a fall in trade. Sales in November were the lowest in the 22-year history of the CBI's Distributive Trade Survey.
Today's figures show that December is the first time since February that monthly sales have not fallen year on year.
However, while the figures are more positive than the past six months and better than expectations, the volume of sales is still lower than retailers would normally expect at this time of year, a balance of -11 per cent.
Ian McCafferty, CBI chief economic advisor, said: 'Christmas, in retailing terms, is coming later and later each year as consumers play chicken with the high street and delay their spending in the expectation of late price cuts as the big day draws nearer.
'And this year, with Christmas Day falling on a Sunday, it is likely that most people will leave their shopping until late, and then continue right until the shops close their tills on Christmas Eve.'
Groceries, footwear and clothes were the growth sectors of the retail market, according to the survey. Sales of furniture, carpets, hardware and DIY goods remained in the doldrums.
John Longworth, executive director of Asda and chairman of the CBI's DTS Panel, added: 'Retailers have been pinning their hopes on Christmas bringing some festive cheer after months of depressed trading, and these figures are better than expected.'