The Director General of the British Retail Consortium, Stephen Robertson has said that the Olympic period was "an unknown."
He added that "shoppers were more interested in watching the magnificent Olympics rather than getting out on to the high-street."
Mr Robertson also said that there was hope for Christmas as retailers prepare for the festive season; "let's cross our fingers that the good feelings we got out of the Olympics and the Paralympics carry on in to the fourth quarter of this year."
More top news
Republican frontrunner said Ted Cruz's father was with JFK's killer at the time of the assassination.
Sajid Javid has ordered an immediate investigation into the circumstances around the collapse of British department store BHS.
Three people have been arrested in connection with the discovery of a man's body in a reservoir