The rise in online sales is the driving force behind early summer Sales on the high street weather rather than the lacklustre weather, according to consultancy PwC.

New research found that three-quarters of 100 high street retailers were on Sale or advertising promotions last week, which is double the figure from 2009 but in line with the previous two years.

The research showed that 73% of high street retailers were on Sale this time last year and, in 2011, 70% went on Sale early. The average discount being advertised is 47%, which is the same as during 2012 and slightly up from 45% in 2011 and 2010.

Christine Cross, chief retail adviser to PwC, said:  “It’s easy to get the impression that all the high street and online too is on sale and that this is a reaction to the absence, or hopefully late appearance, of summer this year. However, the truth is that Sales have been starting earlier each year and this year just continues the trend.

“I believe that online is impacting our seasonal buying cycles. Autumn lines have been previewed since early May and the ability to reserve ahead is commonplace. So, for the British fashion buyer there are two options - buy ahead and get your pick of the trends, or wait and get a bargain. The British consumer wins both ways in this ‘total retail’ world.”