A parliament is generally recalled as a result of events of major national importance, thus allowing members to hold an emergency debate on issues relating to those events.
In the United Kingdom, decisions as to whether the House of Commons or House of Lords should be recalled are the responsibility of the Speakers of those individual bodies, and are usually taken following a request from the government.
[1] This follows a 2001 recommendation from the Hansard Society Commission on Parliamentary Scrutiny that "the Speaker of the Commons should have the ability to recall Parliament at times of emergency".
[2] This is codified by the House of Commons Standing Order 13.
[3] In the United Kingdom, Parliament has been recalled on the following occasions: