Thursday's recall of Parliament will be the fourth time David Cameron has interrupted MPs' holidays.
- In April, the death of former Prime Minister Margaret Thatcher sparked a full day of tributes in both the Commons and the Lords
- MPs were recalled twice during the 2011 summer recess - first for a statement about phone hacking and the police in July, and then again in August after riots broke out
- Previously, recalls had been relatively rare - the next occasion was a recall in April 2002 to mark the death of the Queen Mother
- Parliament was also recalled three times in the wake of the 9/11 terrorist attacks and subsequent military action