Harlequins have slipped to four straight defeats in all competitions since their 30-27 victory at Leeds on 4 December.
Quins’ only win in their last six home games was 35-29 against Gloucester in the Guinness Premiership on 28 November.
Leeds Carnegie’s run of three straight wins came to a halt at the hands of Bath on Saturday, however Leeds have won their last two away games at Bucuresti and Newcastle.
The Londoners have beaten Leeds on the last three occasions they have met, whilst Leeds have not won at the Twickenham Stoop since a 16-9 victory in the Premiership on 29 November 2003.
Referee: Dean Richards (30th Premiership game)
Postponed due to adverse weather
This Preview was originally written for the weekend of 8th January and will be revised nearer the rescheduled match date.