LONDON The British parliament's upper house, the House of Lords, on Monday begins debating legislation which would give Prime Minister Theresa May the power to trigger Britain's exit from the European Union.
Earlier this month the lower house, the House of Commons, passed the legislation without amending it.
The legislation is not expected to be blocked by lords, but the government could be forced into making concessions as it does not have a majority in the upper house.
Here is the party affiliation of the House of Lords' 805 members, according to parliament's website:
Liberal Democrat: 102
Below is the expected timeline for the remaining stages of the bill:
Feb. 20-21 - Second reading
Members of the House of Lords hold a two-day debate on the key principles and main purpose of the bill. It is an opportunity to flag up concerns or areas where they believe amendments are needed but they are not expected to vote on specific details.
Any member can speak, and 190 have signed up to do so.
A vote is not expected at the end of the second reading on whether to progress the bill to the committee stage, but one could be called. The bill is highly unlikely to be defeated at this stage.
Feb. 27 and March 1 - Committee stage
At the committee stage, a detailed examination and discussion of proposed amendments takes place and amendments may be voted on. Any member can speak and can discuss an issue for as long as they want.
So far Lords have put forward 11 pages of proposed amendments which would add conditions to the legislation.
Amendments on guaranteeing the rights of EU citizens living in Britain, and calling for the government to give parliament a vote on the final Brexit deal are expected to attract the most support.
March 7 - Report stage and third reading
Lords debate the final wording of the bill and may make and vote on further amendments.
If the bill has been amended by the Lords, these amendments will be passed back to the House of Commons for approval. The bill will be passed back and forth, a process known as 'ping pong', until both houses agree on the wording of the bill. There is no time limit to this process.
There is no set time period within which the Commons must consider any Lords amendments, but it is amended by the Lords the bill is expected to return to the commons as soon as possible, most likely the week of March 13.
The government has said it expects this process to be completed in time for May to stick to her timetable of triggering formal divorce talks by the end of March.
The House of Lords is not expected to want to be seen frustrating the referendum result, so if the Commons rejects any amendments it puts forward, it may not push to reinstate them.
(Compiled by Kylie MacLellan; editing by Guy Faulconbridge)