After a great deal of complicated processes in a Government Bill, the Bill will be passed from the House of Commons to the House of Lords. In this stage, they will carry on a ‘ping-pong’ between the two chambers. As a revising chamber, the main function is amendment of the Bills, however the upper chamber is also able to reject and delay a bill for up to one year(exception of money bills). For example, in 1990, the War Crimes Bill was rejected by the Lords which cause one-year delay of this bill(Neil.M,2001); Another example is the controversial Health Bill, which has already been amended 137 times for securing Lords approval(Colin.L&Val.O,2014). Moreover, there are some bills about local taxation and spending are not defined as ‘money bills’, so the power of the lords are still significant. Furthermore, ‘The Lords have great potential power in the final year of a Parliament, since a government knows that a defeat in the Lords will block legislation unless it wins another election’(Budge.I&McKay.D&Newton.K&Bartle.J,2007). The house In this stage, the government defeats has happened 11 times from 2013-2014, and has happened 362 times in recent ten years(http://www.parliament.uk/about/faqs/house-of-lords-faqs/lords-govtdefeats/ﾧ); Sometimes, the House of lords even can made a bill fail; For example, Terrorism Act 2008, which had passed in the House of Commons though with a 36 Labour MP rebellion, it failed finally when it came back to the House of Commons again. Besides, the upper house has enough time to debate bills about detail than the lower chamber, obviously, which means it is capable of ensuring that a bill can be well drafted and internally coherent(Bill.J&Philip,2001). Thus, the House of Lords has the role which is complementary to the House of Commons(Bill.J&Philip,2001).
Lords also play important roles in the Select Committees which are controlled by the both Houses, the upper focus on European Union, Science and Technology, in addition, it also assumes some Joint Committees together with the lower House. The most powerful Committee from Lords is the European Union Committee which is in charge of scrutiny of draft European legislation. The EU committee has organised a good reputation as a thorough and informed organisation which issues reports more extensively than its counterpart in the Commons(Bill.J&Philip,2001). Another important Committee is The Select Committee on Science and Technology which focus on science and technology. It is a essentially non-partisan Committee, all of the members inside are specialists from kinds of area. Moreover, Joint Committee on Human Rights, it follows Lords procedures, although is chaired by an MP. （Bill.J&Philip,2001）
The last major function of the House of Lords is provision of expertise for the Parliament. Nearly every members are appointed by the Prime Minister as they have had notable careers in the military, the sciences, in industry and kinds of areas, or the house of common itself(Julian.K,2010). This house contains hundreds of experts who can recognise faults in Bills, which secure that not only amending legislation, but also when they scrutinise government, Lords have more potential for a more thorough consideration than is possible in the Commons(Bill.J&Philip,2001).
As everyone knows, the United Kingdom is a constitutional monarchy country, the monarch has no power, however the two main powers out of three are legislature and executive which