House of Lords: What is it and what could Labour replace it with?
House of Lords could be abolished if Labour wins the next election.
Lords chamber is centuries old, and replacing it would represent a huge change to the UK's political system. 
House of Lords is part of the UK Parliament. Also known as the Upper Chamber, it is independent from the House of Commons - where Members of Parliament (MPs) debate and vote on new laws.
Members of the Lords are called "peers". Like MPs, they also scrutinise the work of government and recommend changes to proposed legislation.
Unlike MPs, however, peers are not elected. The majority are appointed by the monarch on the advice of the prime minister.
While many peers have worked in politics - including some former MPs - others are experts in areas such as science or the arts.
Most peers stay in the Lords for life - although some decide to retire.
re are currently 785 peers, making the House of Lords the second largest parliamentary chamber in the world. Only China's National People's Congress is bigger. 
Conservatives make up the largest group with 265 peers. There are 173 Labour peers, and 185 Crossbenchers - peers who are not affiliated to a particular party.
Membership of the Lords has increased since 2000, according to the House of Lords Library.
re are three main ways to join:
Most Lords are entitled to a £332 daily allowance for each sitting day attended - although they can choose not to claim.
Some receive a salary - like the Lord Speaker and government ministers. Salaried peers cannot claim the daily allowance.
urrent system is "undemocratic" and "indefensible", according to Labour leader Sir Keir Starmer.
Labour says the PM should not have the power to appoint peers, highlighting recent controversial appointments such as businessman Peter Cruddas. 
Instead of the Lords, Labour wants an elected second chamber called the Assembly of the Nations and Regions.  
It could have around 200 members from across the UK. However, the way they would be chosen - and how long they would serve - remains to be decided. 
Sir Keir says the new system could be introduced within the first five years of a Labour government.
Labour will set out further details, including a timeframe, closer to the next election.
Gridlock
Former Cabinet Minister Simon Clarke MP has called the plan "a terrible idea".
"Anyone who has looked at the institutionalised gridlock in US politics can see the utter stupidity it would be to create an elected upper house".
Political gridlock can make it difficult to pass new legislation. In the US, this can happen when control of both houses of Congress is split between Republicans and Democrats, meaning one house can block attempts from the other to introduce new laws.
Loss of expertise
Abolishing the Lords could also result in a loss of expertise, says Jess Sargeant from the Institute for Government think tank.
"An appointments system can bring in experts - like former doctors and supreme court judges. There is some speculation about whether these sorts of people would be willing to stand in an election."
Undermining the Commons
If the new chamber's members considered themselves more representative of the UK than MPs, there is a risk they may undermine the Commons by blocking new laws, adds Ms Sargeant. 