The Commons timetable is set in advance - and individual 
MPs have few opportunities to raise issues at short notice. 
The House gets round this problem by calling an 
Emergency Debate - and every day at 3.30, after 
ministerial questions, MPs have the opportunity to 
request such a debate under Standing Order Number 24. 

Very few Emergency Debates actually take place - usually 
at times of national crisis - but requests for debates are 
relatively frequent. This is because the proposer has three minutes to make a case for the debate - and quick-witted MPs can use the time to air their grievances, despite knowing that the Speaker will not allow the actual debate to take place.