Filibustering is the practice of an MP making a very long speech. This prolongs a debate - the purpose of this is to attempt to prevent a Bill passing through Parliament. MPs who do this hope that the House will run out of time to complete all the stages of the Bill before the session is over. Filibustering was used to great effect by Irish MPs in Parliament in the 19th Century. These MPs wanted independence for Ireland and so held up all kinds of legislation to cause problems for the Government.